Appendix_B_-_NAMA_151073_Final_Geoarch_Report_Sept2011.pdf

GEOARCHEOLOGICAL INVESTIGATION FOR THE

WASHINGTON MONUMENT VISITOR SCREENING FACILITY

NATIONAL MALL AND MEMORIAL PARKS

DISTRICT OF COLUMBIA

FINAL TECHNICAL REPORT

CONTRACT NO. 1443C2000090700, TASK ORDER T2011090248

PREPARED FOR:

NATIONAL PARK SERVICE

DENVER SERVICE CENTER

12795 W. Alameda Parkway Denver, Colorado 80225-0287 and

BEYER BLINDER BELLE

3307 M Street, NW, Suite 301 Washington, D.C. 20007

PREPARED BY:

THE LOUIS BERGER GROUP, INC.

1250 23rd Street NW, 4th Floor Washington, D.C. 20037 September 2011

GEOARCHEOLOGICAL INVESTIGATION FOR THE

WASHINGTON MONUMENT VISITOR SCREENING FACILITY

NATIONAL MALL AND MEMORIAL PARKS

DISTRICT OF COLUMBIA

FINAL TECHNICAL REPORT

CONTRACT NO. 1443C2000090700, TASK ORDER T2011090248

PREPARED FOR:

National Park Service Denver Service Center

12795 W. Alameda Parkway Denver, Colorado 80225-0287 and

BEYER BLINDER BELLE

3307 M Street, NW, Suite 301

Washington, D.C. 20007

PREPARED BY:

Charles LeeDecker

THE LOUIS BERGER GROUP, INC.

1250 23rd Street NW, 4th Floor

Washington, D.C. 20037

WITH:

Daniel P. Wagner GeoSci Consultants, LLC

4410 Van Buren Street University Park, Maryland 20782

September 2011 i

EXECUTIVE SUMMARY

On behalf of the National Park Service, Denver Service Center, The Louis Berger Group, Inc. (LBG), completed a program of geoarcheological testing for the proposed Washington Monument Visitor Screening Facility in Washington, D.C. The National Park Service (NPS) is evaluating various alternatives that would improve security and visitor screening at the Washington Monument. In 2004- 2006 the NPS completed a program of security improvements for the Washington Monument that included a comprehensive landscape solution for a perimeter vehicular barrier system and an associated landscape design. The current visitor screening facility, intended as a temporary facility, stands at the base on the Monument’s east face. Removal and replacement of this facility is the action that is now being evaluated under an Environmental Assessment (EA).

This geoarcheological study was designed to support the EA and ongoing Section 106 consultation for the Visitor Screening Facility, with specific attention to possible impacts to archeological resources. The goals of this study were to assess the general condition of the landscape, focusing on identification of prehistoric or historic landscapes that might contain archeological resources.

A total of 12 borings was made in the study area (or area of potential effects), which was defined to include the security zone established in the 2004-2006 program. This is an elliptical area of roughly 14 acres, centered on the Monument and defined by a low retaining wall and pathway. Using a Geoprobe, 12 borings were placed in a cruciform pattern oriented on the north-south and east-west axes from the Monument. The borings were advanced to depths ranging from 15 to 26 feet below ground surface, which was sufficient to reach the level were a buried natural landscape would have been present, given favorable preservation conditions.

Although the testing confirmed that the entire study area is covered by fill deposits, the results were somewhat surprising in that eight of the 12 borings contained an intact buried landscape. Fill depths ranged from roughly 6 to 20 feet, with greater depths in the areas nearest the Monument. The buried surfaces were found at elevations ranging from about 15 to 22 feet above mean sea level. These elevations depict the natural contours of the site as an elevated landform overlooking the original confluence of Tiber Creek and the Potomac River. This buried natural landscape, represented by a plowed surface soil (Ap-horizon or plowzone), was typically represented by a dark brown silt loam showing evidence of plowing. In some cases the Ap-horizon had been slightly truncated, indicative of minor grading of the landscape during the historic period. The fill deposits overlying the natural landscape would date to after 1880, when foundation work was completed and a raised terrace was created at the base of the Monument. Beneath the buried landscape represented by the Ap-horizon, an older landscape surface or paleolandscape is recognizable by a blanket of loess that formed during the Younger Dryas climatic episode, roughly 10,850 to 9550 BC.

This study’s findings point to the need for further consideration of possible effects of the project on possible archeological resources. The previously identified Monument Grounds Site (51NW35) is the resource of primary concern, but its location cannot be pinpointed with any accuracy. Alternative project designs are now in the conceptual stage, so details regarding footprints and associated ground disturbance are speculative. Project alternatives that would place the footprint of the new screening facility within the existing plaza area might be the most benign in terms of potential effects on archeological resources, provided that any ground-disturbing activities are confined to the zone of post-1880 fill deposits that are of no archeological interest. The “New Approach through the Landscape” alternative would involve a below-grade concourse between the Monument and the Lodge, where the buried landscape was identified in Borings WAMO-4, WAMO-5 and WAMO-8; if this project alternative is chosen, careful attention should be given to its potential impact to archeological resources.

ii

PUBLIC SUMMARY

As an element of the planning studies for the Washington Monument Visitor Screening Facility, the National Park Service has sponsored a geoarcheological study to determine whether any important archeological resources could be affected by the construction of the new facility. The new visitor screening facility will be located within the Washington Monument Grounds, at the heart of the city’s monumental core area. The Monument Grounds were set aside as a public reservation in the L’Enfant city plan of 1790. In the L’Enfant Plan the Monument Grounds correspond to the intersection of two broad “avenues” of public land, one extending south from the President’s House, the other extending west from the Capitol. Although the Washington Monument has been a public reservation since the founding the City of Washington, it does have an interesting history, and much of that history is written in the archeological record.

A great deal of historical information is available for this area because of its association with the Washington Monument, which is a national icon. But other than its general topography, the present condition of the site offers little evidence of the natural environment of the District as it existed in the late eighteenth century when the capital city was founded. Before the City of Washington was laid out in 1791, the Washington Monument Grounds bordered the channel of Tiber Creek, one of the District’s natural inland waterways. The Washington Monument Grounds were then on the south bank of Tiber Creek, partially on dry land and partially within the creek bed. As the city developed in the nineteenth century, Tiber Creek was transformed first into the Washington Canal, then into the B Street Sewer, and then covered over and turned into Constitution Avenue.

Before European colonization, Native American (Indian) groups camped and built villages along the shores of the Potomac and Anacostia rivers, as well as the inland waterways such as Rock Creek and Tiber Creek. The Potomac River valley was inhabited by Native Americans starting at about 13,000 years before the present. Until about 4,000 years ago, the region was used by small transient foraging groups; the archeological evidence of their camp sites typically consists of the stone tools and the debris that resulted from the manufacture or resharpening of stone tools. Around 2000 BC, people began quarrying huge numbers of cobbles from the hill flanks along Rock Creek. These cobbles were shaped into rough oval forms, then carried to campsites for final trimming into broad spearpoints of the Savannah River style. The people who made broadspears also made tub-shaped cooking vessels by carving soapstone, which was hacked out of bedrock in the District of Columbia and nearby areas of Maryland and northern Virginia. A few centuries later (about 1000 BC), ceramic pots replaced these soapstone vessels. The Native American societies were linked by long-distance trade networks, so the stone bowls reached groups living far away from the soapstone sources.

Long-distance exchange seems to have alternately waxed and waned over the following 2,000 years.

Chipped-stone tools, tubular stone smoking pipes, and other distinctive export items from the Adena culture of the Ohio Valley were deposited in well-appointed burials in Delaware in the period from around 400 BC to AD 1. These artifacts presumably were carried down the Potomac eastward from the Adena heartland. After the demise of the Adena mortuary cult, a regional trade network continued in the Middle Atlantic region, circulating items such as purplish argillite from New Jersey and rhyolite from central Maryland.

About AD 600 to 1000, long-distance trade routes were re-established, again in a context of mortuary ritual. This time, the network linked Middle Atlantic societies to groups in New York, New England, Ontario, Michigan, and Ohio. Distinctive items exchanged among these peoples included antler combs, fossil sharks’ teeth, polished stone gorgets, and stone platform pipes with tulip-shaped bowls. A cremation burial containing such artifacts, and dated to about AD 750, was discovered several years ago iii at the mouth of Rock Creek, beneath a ramp to the Whitehurst Freeway. The same site produced evidence of a later occupation by maize (corn)-growing villagers in the Late Woodland period (AD 1000 to 1600). At the time of first contact with English explorers in 1608, a major village of the Algonquian-speaking Nacotchtanks was located beside the Anacostia River (which was named for this group).

In the early 1800s the landscape along lower Tiber Creek had not changed much from its initial configuration, and the Washington Monument Grounds were part of an undeveloped area that was used primarily for pasture. Before the Civil War, construction of the Washington Monument progressed slowly and the surrounding grounds were largely vacant, used only for pasture. During the Civil War construction of the Monument ceased and the grounds were used for cattle grazing and military maneuvers. The Monument Grounds acquired names such as Beef Depot, the Cattle Meadow, and the Washington National Cattle Yard. As the war progressed, various quarters, storehouses, stables, pens, sheds, and a slaughterhouse appeared. During the final phase of construction of the Monument, the grounds were covered with shops, machinery, a railroad siding, and possibly barracks for workmen.

Landscaping of the grounds, completed in the 1880s, included construction of carriageways and pedestrian paths through the grounds.

World War I returned the city to a wartime mentality, and once again the Washington Monument Grounds were given over, at least partially, to grazing. Recreational demands for the city’s public lands increased during the early twentieth century; one result of this was the appearance of baseball diamonds, football and lacrosse fields, tennis courts, an archery range, a croquet court, a miniature golf course, and a swimming pool and bathhouse complex. During World War II part of the grounds was taken over by temporary military office buildings. The Age of the Automobile brought a series of changes to the adjacent roadway system in the late twentieth century.

The present geoarcheological study included a combination of archival research and field investigation of the site. The archival research focused on the site’s physical development and historic uses. Historical maps were especially important, and these were available from a variety of sources. Other sources included many historical studies that describe the city’s natural and early historic environment and its physical development for the urban period.

The geoarcheological field investigation was conducted by a soil scientist who used a truck-mounted probe that can examine deeply buried soils with minimal impact to the landscape. The test borings showed that the entire study area is covered by highly variable earthen fill deposits, but the results were somewhat surprising in that eight of the 12 borings contained evidence of the landscape as it appeared before 1880 when construction of the Monument was completed. These results point to the possibility that important archeological resources may be present on the Monument Grounds.

Of potentially the greatest interest is a Native American occupation of the Monument Grounds that is known on the basis of artifacts collected in the late 1800s. This artifact collection, now held by the Smithsonian Institution, includes artifacts that Native American use of the area for at least 7,000 years.

Other potential archaeological resources that could be present include features related to the construction of the Washington Monument, such as a workshop, barracks, or masonry debris, or resources associated with the Civil War-era occupation of the Monument Grounds.

iv

TABLE OF CONTENTS

Section Page

EXECUTIVE SUMMARY............................................................................................................ i PUBLIC SUMMARY ................................................................................................................. ii LIST OF FIGURES ..................................................................................................................... iii LIST OF TABLES ...................................................................................................................... iii

INTRODUCTION

Scope and Location of Study Study Goals and Methodology Previous Investigations

OVERVIEW OF HISTORIC LANDSCAPE DEVELOPMENT

Natural Setting Prehistoric and Colonial Washington The City of Washington Early Growth of the Capital, 1791 to 1847 Construction of the Washington Monument and the Initial Landscape Design, 1848 to 1889 Changes through the McMillan Plan and Other Early Twentieth-Century Plans, 1889 to 1943 Changes from the Mid-Twentieth Century to the Present, 1943 to 2011 Expected Potential for Archeological Resources

SURVEY RESULTS

DISCUSSION AND MANAGEMENT RECOMMENDATIONS

Discussion of Results Management Recommendations

REFERENCES CITED AND BIBLIOGRAPHY

APPENDIX A: GEOARCHEOLOGICAL ASSESSMENT REPORT .................................................. A-1 Daniel P. Wagner

APPENDIX B: RADIOCARBON DATE REPORT ........................................................................ B-1

APPENDIX C: NADB FORM ................................................................................................. C-1 v

LIST OF FIGURES

Figure Page

1 Location of the Washington Monument 2 Study Area 3 Washington Monument Study Area, 1791 4 Prehistoric Artifacts from the Washington Monument Site 5 Washington Monument Study Area, 1818 6 View of Washington Monument During Construction, First Phase 7 Downing Plan for the Mall 8 Washington Monument Study Area, 1857 9 Washington National Monument Cattle Yard 10 View of Washington Monument During Construction, Second Phase 11 Bird’s Eye View of Washington Monument, 1883 12 Washington Monument Study Area, 1887 13 Washington Monument Study Area, 1903-1921 14 Washington Monument Study Area, 1930 15 Washington Monument Study Area, 1948 16 Location of Geoarcheological Borings 17 Reconstructed Stratigraphic Sections

LIST OF TABLES

Table Page

1 Summary of Geoarcheological Borings

INTRODUCTION

SCOPE AND LOCATION OF STUDY

On behalf of the National Park Service, Denver Service Center, The Louis Berger Group, Inc.

(LBG), completed a program of geoarcheological testing for the proposed Washington Monument Visitor Screening Facility in Washington, D.C. Because of the need for heightened security at the Washington Monument that followed the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City and the terrorist attacks of September 11, 2001, the National Park Service (NPS) is evaluating various alternatives that would improve security and visitor screening at the Washington Monument. In 2004-2006 the NPS completed a program of security improvements for the Washington Monument that included a comprehensive landscape solution for a perimeter vehicular barrier system and an associated landscape design. The current visitor screening facility, intended as a temporary facility, stands at the base on the Monument’s east face. Removal and replacement of this facility is the action that is now being evaluated under an Environmental Assessment (EA). Construction of the new visitor screening facility would complete the overall program of security improvements the Washington Monument. This geoarcheological study was designed to support the EA with specific attention to possible impacts to archeological resources from the removal and replacement of the screening facility.

The Washington Monument is a formal landscape that is managed by the NPS’s National Mall & Memorial Parks (NAMA). This landscape is bounded on the north and south by Constitution and Maine avenues, and on the east and west by 14th and 17th streets, NW (Figure 1). For purposes of this investigation, a more narrowly defined study area, or area of potential effects (APE), has been defined, coinciding with the security zone established by the 2004-2006 program; this area is defined by an elliptical wall centered on the Monument and measures approximately 1,000 feet east-west by 775 feet north-south (Figure 2). All ground-disturbing activities that could potentially impact archeological resources would be confined to this area, based on the design alternatives that are now under consideration. New alternatives or modifications to existing alternatives could emerge during ongoing design development and agency consultation;

however, it is likely that areas of ground disturbance will be confined to the area immediately surrounding the Monument and on the axis between the Monument and the Washington Monument Lodge, where various ramps, walkways, and underground screening facilities might cut into the existing landscape. Project elements that would require ground disturbance include below-grade construction of a concourse or walkway between the Monument and the Monument Lodge; construction of a new entrance to the Monument, below the grade of the present plaza;

and extension of the existing elevator system to a below-grade screening facility.

STUDY GOALS AND METHODOLOGY

The goals of the geoarcheological study were to assess the general condition of the landscape, focusing on identification of prehistoric or historic landscapes that might contain archeological resources. These goals can be expressed as a number of specific questions that were developed to guide the investigation:

FIGURE 1: Location of the Washington Monument SOURCE: USGS 7.5-Minute Quadrangle, Washington West, DC-MD-VA 1965 (Photorevised 1983)

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Does the study area contain areas of natural landscape associated with the bank of the lower Tiber Creek?

What is the likely level of integrity associated with potential prehistoric and historic archeological resources in subsurface contexts in the study area?

What effect have the processes of historic land use and formal landscaping of the Washington Monument Grounds had on landscapes that might contain significant archeological resources?

How extensive is the disturbance associated with existing utility lines in the study area?

Given the widespread presence of fill deposits across the Monument Grounds, it was necessary to employ mechanical excavation techniques to systematically examine buried soils and possible landscape surfaces. The field investigation was completed with a direct-push geotechnical sampling machine, generically known as a Geoprobe. The Geoprobe recovered continuous soil columns in 4-foot increments with minimal damage to the landscape.

The test locations were distributed to broadly sample the study area. All test locations were plotted on a scaled base map and recorded using GPS equipment with sub-meter accuracy. In all cases the individual tests were advanced to natural soils. Test locations were placed along four transects north, east, west, and south of the Monument. No tests were placed within the paved plaza because of public safety concerns and the logistics that would be necessary to avoid damage to the hardscape. Avoidance of utility lines was also a major concern. Historical maps and surveys were reviewed prior to selection of boring locations, and the lack of complete as-built drawings for the most recent (2004-2006) security improvement program required a cautionary approach, especially in the areas immediately adjacent to the plaza where active water and electric lines were expected.

The soil core borings were provided to a professional geomorphologist for off-site analysis. The geomorphologist prepared detailed profile descriptions for each soil column in accordance with standard techniques and nomenclature for field description of soils. The geomorphological study was completed by Dr. Daniel Wagner of GeoSci Consultants, Inc., LBG’s consulting geomorphologist. Results of that study are presented as Appendix A of this document. Individual auger tests were designated with a prefix “WAMO” (to denote Washington Monument) and a numeric suffix. Under normal conditions a detailed soil profile description is compiled for each test in accordance with standard techniques and nomenclature for the field description of soils.

Fill soils, because they are highly variable and reflect anthropogenic rather than natural processes, are not normally described at this level of detail. Detailed descriptions were made for all natural soils.

Fieldwork was completed on June 23, 2011.

PREVIOUS INVESTIGATIONS

A formal Archeological Overview and Assessment Study has not been completed for NAMA, so information on archeological resources in the study area must be extrapolated from previous studies in the surrounding area and other sources. The Archeological Overview and Survey Plan for the National Capital Area (Little 1995) established priorities for the systemwide archeological inventory project. In that document one of the Priority 1 projects was a shoreline study of the Potomac and Anacostia rivers, which would be relevant to four parks, including NAMA. To date this recommended shoreline study has not been completed. Lacking detailed information on archeological resources for NAMA, it is possible only to develop speculative statements regarding existing archeological resources.

Little’s recommendation for a shoreline study stems from the fact that much of the downtown monumental core area, including the Washington Monument Grounds and the National Mall, is situated on the original shoreline of Tiber Creek, one of the District’s natural inland waterways.

Before the City of Washington was laid out in 1790, the south bank of Tiber Creek cut across what is now the Washington Monument Grounds (Figure 3). As a natural shoreline, areas immediately adjacent to Tiber Creek are of archeological interest primarily because such areas were attractive to Native American groups and because the city’s early development was concentrated along its waterfront areas. The modern landscape associated with the study area reflects the filling of Tiber Creek and the creation of the formal landscapes of the Monument Grounds. Because most of the land in the study area consists of fill deposits and formal landscapes, archeological resources associated with earlier historic landscapes, if present, may be found in buried contexts.

Native American occupation in the downtown area around Tiber Creek has been well established despite the urban character of the modern environment. Many artifact collections from sites in the District of Columbia were amassed prior to the advent of modern archeology, and therefore they typically lack specific information about their provenience or location of origin. Among the prehistoric artifact collections from the District of Columbia is an assemblage of 147 specimens from the Washington Monument Grounds that was recently described by Krakker (2005). This collection (Figure 4) is apparently from a site on the south bank of Tiber Creek, although the exact origin is unknown. The collection was obtained in the 1880s and includes artifacts that indicate episodic use of the area for at least 7,000 years. The collection has been cataloged as archeological Site 51NW35-Monument Grounds.

Previous studies within the Monument Grounds and adjacent park land of the National Mall have demonstrated that the archeological record of this area can be quite complex, with physical remains of a great variety of events that vary widely in their historical and archeological significance. Although few archeological studies have been conducted, there are other sources of important information regarding the physical history of this area, which is essential for understanding the archeological record. The NPS has completed various studies, including a Cultural Landscape Report (CLR) for the Washington Monument Grounds (John Milner Associates, Inc. [JMA] 2008), a history of the Washington Monument (Olszewski 1971), a Historic Structure Report (Oehrlein and Associates 1993), and Historic American Buildings Survey (HABS) documentation for the National Mall and Monument Grounds and the L’Enfant- McMillan Plan (HABS 1993a, 1993b, 1994). Archives of the NPS and the National Capital Planning Commission contain a wealth of maps and planning studies that document the site’s physical history. Among the many published histories of the District’s monumental core area, the most useful are Richard Longstreth’s compilation of essays (Longstreth 2002) and John Reps’s (1991) visual history of Washington. A number of geotechnical studies and soil surveys also

Potomac River

Tiber Creek

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FIGURE 3: Washington Monument Study Area, 1791 SOURCE: L'Enfant 1791

Legend Study Area

0 800 1,600400 Feet

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FIGURE 4: Prehistoric Artifacts from the Washington Monument Site SOURCE: James Krakker, Smithsonian Institution provide useful information for understanding the subsurface conditions that characterize the Monument Grounds (Mueser Rutledge Consulting Engineers 2002; Short et al. 1986).

There have been relatively few opportunities for modern archeological investigations on the Monument Grounds. An assessment of the 1980s-era Development Concept Plan for the Washington Monument concluded that the area immediately surrounding the Monument had been so severely disturbed that there was no possibility that archeological resources could have survived (Potter 1983). This assessment refers to a prehistoric artifact that had been collected from the site in 1875 as evidence of Native American use of the area, but concludes that a single, isolated artifact was inconclusive with regard to a possible Native American settlement. As detailed by Olszewski (1971) and others, the building history of the Monument — especially the 1879-1880 underpinning of the foundation and the subsequent landscaping of the adjacent grounds — also suggested that the proposed 1980s-era development would have no effect on archeological resources (Potter 1983).

Archeological investigations for the National Museum of African American History and Culture (NMAAHC) demonstrated that, despite a complex archeological record, some remnants of the natural landscape along Tiber Creek may be preserved beneath deep fill deposits. The NMAAHC site is located on the northeast panel of the Monument Grounds, and historically that site was on the south bank of Tiber Creek. The Phase I study of the NMAAHC site (LeeDecker et al. 2007) included an extensive program of archival research followed by a geoarcheological study and a more standard Phase I archeological survey. The geoarcheological investigations indicated that the site contains areas of a preserved natural landscape surface that correspond to the south bank of Tiber Creek as well as a possible early nineteenth-century landscape surface that was created in conjunction with the extension of the Washington Canal within the channel of Tiber Creek.

Building on the Phase I study, the Phase II study for the NMAAHC (LeeDecker et al. 2008) had two primary goals: (1) delineation of the extent of the natural landscape surface, focusing on the identification of intact prehistoric deposits; and (2) exploration of the northern area of the site, where the Phase I study pointed to a possible buried nineteenth-century surface with associated domestic deposits and possible remains of structures associated with the canal or construction of the Washington Monument. Very few prehistoric artifacts were recovered during the Phase II investigation, so research questions dealing with prehistory could not be addressed. No intact features identified with the Washington Canal were discovered, but a possible remnant of a nineteenth-century carriageway was found that is believed to be associated with the first formal landscaping of the Washington Monument Grounds. The complex stratigraphy throughout the NMAAHC site reflects numerous fill deposits from various sources during the nineteenth century related to the canal’s construction and filling of low areas along Tiber Creek. The combined Phase I and Phase II findings provided information about the historical development of the Washington Monument Grounds, where the landscape changed from open agricultural space to public areas of the nation’s capital, complicated by numerous attempts to build, maintain, and repair an ill-conceived and poorly managed canal.

A series of soil core borings sampled the near-surface soils of the National Mall in the 1980s (Short et al. 1986). These borings were distributed along five east-west transects, with 20 core samples on each transect. The goal of that study was to characterize the physical and chemical properties of the Mall soils, and the borings were limited to the upper 0.7 meter (2.46 feet) of soil. The study noted some of the land use patterns that have influenced the Mall landscape, including filling, construction of temporary buildings, and formal landscaping. Overall, 95 percent of the borings showed evidence of filling, some with multiple discontinuities that reflected a series of filling or grading episodes. More than four in 10 (42 percent) of the soil core borings showed evidence of a buried surface soil (A-horizon). It is assumed that archeological resources may be present in surface soils; these surfaces could represent the natural landscape of the city as it existed before the city was laid out in 1791 or intermediate surfaces formed by the addition of fill soils onto the underlying landscape surface. The investigators noted that some areas of the Mall may have fills that reach a depth of 20 feet, particularly the former channel of Tiber Creek (Short et al. 1986).

A more recent geoarcheological study (LeeDecker 2010) for the National Mall Turf and Soil Reconstruction Project concluded that most areas of the Mall are characterized by soil columns composed of varying amounts of fill over truncated natural soils, a conclusion that is consistent with the Mall’s well-documented landscape history. These findings might be projected to the Monument Grounds, given the broadly similar developmental history of the Mall and the Monument Grounds; however, the geoarcheological study for the Turf and Soil Reconstruction Project did present some intriguing findings. Recognizable tidal flat soils associated with the south bank of Tiber Creek were identified at the 4th Street cistern location, and these represent the best preserved remnants of the natural environment that existed in this area prior to urban development. These soils would have been part of the landscape associated with the prehistoric and early historic periods, and they may have been exploited for aquatic resources. The tidal flats would have not been suitable for occupation, however, so their archeological potential is minimal. Two soil core borings—at the 10th Street and 7th Street cistern locations—contained soils that are characteristic of moderately well-preserved upland natural landscapes. These columns contained a possible loess deposit (wind-deposited silt), raising the possibility that a more ancient landscape surface may be buried beneath the loess. Mapping and characterization of this loess deposit has become a primary research interest for the archeology of the District of Columbia, as the underlying paleolandscape may have been used by very early prehistoric populations.

OVERVIEW OF HISTORIC LANDSCAPE DEVELOPMENT

NATURAL SETTING

The Washington Monument is situated in the Coastal Plain physiographic province, in which surficial geology consists of unconsolidated sediments composed of sands, gravels, and clays of marine or fluvial origin. The thickness of these deposits in the District of Columbia ranges up to several hundred feet, but there also some localized outcrops or exposures of metamorphic rock.

The natural (and now largely obliterated) topography of the downtown area of the District was dominated by a series of recognizable terraces formed in the Coastal Plain sediments. Pierre L’Enfant’s plan for the Federal City (see Figure 3) took advantage of the topography afforded by the remnant terraces, with two of the most elevated sites set aside for the Capitol and the Executive Mansion (the White House). Jenkins’s Hill became Capitol Hill, and Burnes Farm knoll was chosen as the site of the President’s House (the White House). In the L’Enfant Plan the Washington Monument Grounds correspond to the intersection of two broad “avenues” of public land, one extending south from the President’s House, the other extending west from the Capitol.

At the intersection of these Executive and Legislative axes, L’Enfant reserved a site for a memorial statue of George Washington. The Monument Grounds were also known as Reservation 3 in the L’Enfant city plan of 1790; when the public appropriations were renumbered in 1883, it became known as Reservation 2.

Tiber Creek, also known as Goose Creek, drained about half of the downtown area, emptying into a broad, shallow tidal estuary. The headwaters of Tiber Creek began more than 3 miles north of the Capitol; in the downtown area it meandered west toward the Potomac, roughly following the present course of Constitution Avenue (formerly B Street). It emptied into the Potomac River at 17th Street, at which point it was some 700 to 800 feet wide.

PREHISTORIC AND COLONIAL WASHINGTON

The Potomac River valley was inhabited by Native Americans beginning about 13,000 years before the present. Until about 4,000 years ago, the region was used by small transient foraging groups; the archeological evidence of their campsites typically consists of the stone tools and the debris that resulted from the manufacture or resharpening of stone tools. Around 2000 BC, people began quarrying huge numbers of cobbles from the hill-flanks along Rock Creek. These cobbles were shaped into rough oval forms, then carried to campsites for final trimming into broad spearpoints of the Savannah River style. The people who made broadspears also made tub-shaped cooking vessels by carving soapstone, which was hacked out of bedrock in the District of Columbia and nearby areas of northern Virginia and Maryland. A few centuries later (about 1000 BC), ceramic pots replaced these soapstone vessels. The Native American societies were linked by long-distance trade networks, so that the stone bowls reached groups living far distant from the soapstone sources.

Long-distance exchange seems to have alternately waxed and waned over the following 2,000 years. Chipped stone tools, tubular stone smoking pipes, and other distinctive export items from the Adena culture of the Ohio Valley were deposited in well-appointed burials in Delaware in the period from around 400 BC to AD 1. These artifacts presumably were transported down the Potomac eastward from the Adena heartland. After the demise of the Adena mortuary cult, a regional trade network continued in the Middle Atlantic region, circulating items such as purplish argillite from New Jersey and rhyolite from central Maryland.

About AD 600 to 1000, long-distance trade routes were re-established, again in a context of mortuary ritual. This time, the network linked Middle Atlantic societies to groups in New York, New England, Ontario, Michigan, and Ohio. Distinctive items exchanged among these peoples included antler combs, fossil sharks’ teeth, polished stone gorgets, and stone platform pipes with tulip-shaped bowls. A cremation burial containing such artifacts, and dated to about AD 750, was discovered several years ago at the mouth of Rock Creek, beneath a ramp to the Whitehurst Freeway. The same site produced evidence of a later occupation by maize (corn)-growing, Late Woodland (AD 1000 to 1600) villagers. At the time of first contact with English explorers in 1608, a major village of the Algonquian-speaking Nacotchtancks was located beside the Anacostia River (which was named for this group).

The departure of the Nacotchtancks left the Washington area open for British colonists. Among the first to claim patents in this area, in 1663, were Francis Pope and George Thompson. Francis Pope evidently had a sense of humor concerning his surname; he called his patent “Rome” and the adjacent creek “Tiber.” There is no documentary or cartographic evidence that the creek’s alternative name, Goose Creek, was used by anyone prior to Pope. The first known use of “Goose Creek” is on the survey map of the Potomac banks drawn in 1737 by Robert Brooke (Brooke 1737). Louise Hienton’s (1959) reconstruction of the area’s early tracts locates Rome on the upper reaches of the creek, north of the present Capitol. George Thompson patented lands to the south and east of the current project area, and south of Tiber Creek. Thompson was a lawyer who served as Clerk of the Charles County Court. Thompson was granted three tracts totaling 1,800 acres: Duddington Pasture, Duddington Manor, and New Troy. He leased these tracts to Thomas Notley for 40,000 pounds of tobacco. Notley’s title was corrected in 1671, when he patented the tracts collectively as “Cerne Abbey Manor” (Downing 1912).

This area was still a frontier zone in the late seventeenth century. Iroquois hunting and raiding parties were periodically reported in the vicinity of the falls on the Potomac, and a small fort was built by the Potomac Rangers in the vicinity of Fletcher’s Boathouse in 1692 (Fiedel et al. 2005).

Given the insecurity of the area, it is unclear if the early patentees actually settled on their lands;

it should be noted that Augustine Herrman’s map (1673) showed no colonists’ houses in the D.C.

area in 1673.

In 1674 Thomas Notley deeded his Cerne Abbey Manor property to his godson, Notley Rozier, who patented it years later in 1716 as Duddington Manor. In 1711, when the Swiss speculator, Baron von Graffenried, was scouting locations for a colony on the Potomac, Rozier was actually residing far to the south, in the area of present-day Oxon Hill, Maryland. Graffenried’s sketch map also showed a “village,” denoted by three houses, in the area of the present District of Columbia (Graffenried 1714). This is the earliest cartographic evidence of actual settlement in the vicinity of the study area. Notley Rozier married Jane Diggs, and their daughter, Anne, married Daniel Carroll (1707-1764) of the powerful Maryland Irish clan. The eldest son of Daniel and Anne Carroll became known as Charles Carroll of Duddington II (1729-1773). After her husband’s death, Anne Carroll married Benjamin Young. Their son, Notley Young, inherited in 1761 all of Cerne Abbey Manor except the Duddington Manor tract, which remained in the Carroll family (Downing 1912). Charles Carroll’s son, who inherited Duddington Manor, was Daniel Carroll of Duddington (1764-1849) (Clark 1938). The Priggs map of 1790 shows the location of Notley Young’s seat along the Potomac River shoreline, downstream from the mouth of Tiber Creek. The actual location of Young’s seat is at the foot of 10th Street, SW (now L’Enfant Promenade).

THE CITY OF WASHINGTON

Since the establishment of the City of Washington, the Monument Grounds area has been reserved for public use, and therefore its history from 1790 to the present is closely linked to the development of the City’s monumental core area. The formal landscape that is now the Washington Monument Grounds began as the lower reaches of Tiber Creek, and the Monument Grounds straddle the original shoreline of the Creek. During the nineteenth century this natural waterway was transformed first into the Washington City Canal and later into the B Street Sewer. The topography of the Monument Site still reflects the natural drainage system centered on Tiber Creek, but the succession of landscapes associated with the Monument Grounds has brought attendant changes in the topography, circulation system, vegetation, utilities, and standing structures, all of which have a physical expression in the archeological record.

The Cultural Landscape Report for the Washington Monument Grounds (JMA 2008) provides a useful chronology for discussion of the Monument Grounds archeology. The major periods or developmental phases for the urban period are 1791 to 1848, 1848 to 1889, 1889 to 1943; 1943 to the present.

Early Growth of the Capital, 1791 to 1847

Archival information relevant to the Monument Grounds during the early nineteenth century is virtually non-existent. Reservation 3 remained a poorly drained, undeveloped area that was used primarily for pasture (HABS 1993a). Construction of the Washington City Canal certainly altered the northern, inland shoreline of Tiber Creek, but the southern shoreline may have remained untouched by development.

At the end of the eighteenth century, as already mentioned, the shorelines along the mouth of Tiber Creek cut across the landscapes that are presently known as the Washington Monument Grounds and the Ellipse (Figure 5). The Tiber meandered across the downtown area west toward the Potomac, roughly following the present course of Constitution Avenue (formerly B Street).

Across the Monument Grounds, the Tiber’s south bank meandered northeast to southwest, so that a portion of the Monument Grounds would have been in the channel of the creek and the adjacent mud flats.

By 1800 lower Tiber Creek had not changed much from its initial configuration, although the City’s outline was beginning to take shape with the construction of major government buildings and their connecting avenues. L’Enfant envisioned a canal that would allow goods easily to reach the interior of the city, facilitating commerce and building construction in the downtown

³

FIGURE 5: Washington Monument Study Area, 1818 SOURCE: King 1818

Legend Study Area

0 1,500 3,000500 1,000 Feet

0 300 600 900100 200 area. The Washington City Canal would connect the Potomac and Anacostia rivers via Tiber and James creeks, thereby facilitating traffic between Georgetown and the deepwater ports on the Anacostia. River traffic between these points was difficult because of tidal fluctuations, a problem that was would be addressed by construction of an inland canal. L’Enfant’s plan featured a narrow canal channel, or prism, that would extend along B Street from the interior of the city to the mouth of Tiber Creek at 17th Street.

The first phase of canal construction, completed during 1810-1815 under the supervision of Benjamin Latrobe, did not fully realize L’Enfant’s plan; in its original configuration the canal followed the existing banks of the Tiber as far upstream as 6th Street, where the western lock raised the water level 4 feet above low tide (Stapleton 1980). The canal, as well as the lower Tiber Creek, was quite shallow, so only boats with drafts of 3 feet or less were allowed to enter

it. The mouth of Tiber Creek served as a turning basin for canal boats, and a wharf projected into the mouth of the creek at the foot of 17th Street.

Early nineteenth-century maps (DeKrafft 1846; Elliot 1822; King 1918) show that the canal channel had been extended across the northern margin of the Monument Grounds by 1822, indicating that some filling had occurred by that date (see Figure 5). By 1833 the C&O Canal had been extended from its existing terminus at Rock Creek to the foot of 17th Street, thereby allowing a continuous inland passage from the Navy Yard upstream to points far above the Falls of the Potomac. This extension of the C&O began at the basin on Rock Creek near H Street, cut through Easby’s Point to near 22nd Street, and then followed B Street to 17th Street, where a lock lowered the water level to the basin at the mouth of Tiber Creek. The 17th Street wharf was built in 1807 and expanded within a few years.

The canal prism was simply a flat-bottomed ditch with sloping banks. In scale, the Washington City Canal was grand. In its original design, the channel itself was 80 feet wide and flanked on both sides by two 80-foot-wide streets (HABS 1993a; Heine 1956). Typical canals of the period were designed with a bottom width of only 12 feet and a width of 22 feet at the towpath height;

the sides of these canals were built with a 1:1 slope to a depth of 3 feet (Stapleton 1980).

Extension of the canal through the lower Tiber Creek would have been more a matter of filling the channel and forming an appropriately sloped bank to support a towpath. Filling the creek channel, or at least construction of a bulkhead for a towpath, was necessary for the functioning of a canal. The towpath would have been on the inland side of the canal, which would have required alteration of the north bank of Tiber Creek, as has been demonstrated during the previous archeological investigation of the Ellipse (LeeDecker 2006). The typical canal prism widths were calculated to accommodate the passage of canal boats or barges, so the typical prism cross section represented a minimum size. Sections of the Washington City Canal that were built in lower Tiber Creek were probably much wider than 22 feet, owing to the cost of filling the creek channel as opposed to excavating a channel through dry ground. Views of the Washington City Canal in the National Mall area typically illustrate a channel that is much wider than 22 feet.

Construction of the Washington Monument and the Initial Landscape Design, 1848 to 1889

The January 31, 1848, Congressional authorization of a monument to George Washington led to the first phase of construction on the Monument Grounds. Under the jurisdiction of the

Washington National Monument Society, the initial work progressed slowly, hampered by a lack of funds and political interference from the Know-Nothing party. The chosen site for the Monument was near the center of Reservation 3, but because of the marshy soils, the Monument foundation was laid at a location somewhat south of the Capitol latitude and east of the White House longitude, thereby contravening the perfect orthogonalism of the L’Enfant Plan. (The precise intersection of the Executive and Legislative axes was marked by a monument known as the Jefferson Pier, erected in 1804). Construction began according to the Robert Mills design, which called for steps at the base of the shaft. As a construction site the adjacent grounds contained various sheds, an engine house, a saw house, a stone cutter’s shop, carpenter’s shop, a smith’s shop, a cement house, and a stable (Figure 6). The initial stages of the work progressed fitfully, delayed by lack of a steady source of funding, until 1861, when construction was interrupted by the Civil War (JMA 2008).

Construction of the Smithsonian Institution began in the same year that construction of the Monument was authorized, and this was followed by efforts to improve the public grounds in the downtown area. Ignatius Mudd, first Commissioner of Public Buildings under the newly created Department of the Interior, commissioned Andrew Jackson Downing, the leading American landscape architect of the day, to prepare plans for the Mall. Downing’s plan was a series of six gardens or “scenes” that connected the grounds of the Capitol, the White House, and the Smithsonian (Figure 7). Downing’s designs featured serpentine paths and carriageways that afforded naturalistic, picturesque views. One of the most distinctive features of Downing’s plan for the Monument Grounds (which he called Monument Park) was a suspension bridge across the canal at 15th Street. Although the suspension bridge appears in many late nineteenth-century views of the Mall, it was never built. Aside from the Smithsonian grounds and the Ellipse (President’s Park), little of Downing’s vision for the Mall was implemented before the Civil War. Drowned in 1852 as a result of a steamboat accident, Downing never saw his designs realized.

Andreas Boschke’s map of the District of Columbia, which was published in 1857 (Figure 8), illustrates the Downing-inspired landscaping for the Smithsonian and the Ellipse. Much of the Monument Grounds still formed a tidal basin at the mouth of Tiber Creek, and the areas of dry land were undeveloped except for the partially completed Washington Monument.