Oxon Hill Manor (18PR175), or the Addison Plantation, as it is sometimes called, was a large agricultural plantation occupied from the early 18th through the early 20th centuries in Prince George’s County, Maryland. Archaeological excavations revealed a domestic compound, consisting of numerous foundations, cobble walkways, brick walls, wells, fence lines, and cellars, dating from c.1711 through the early 20th century.

Acquired by John Addison in 1687, the site was the estate of successive generations of the Addison family until 1810, when Walter Dulaney Addison sold most of the original property to Zachariah Berry. The Berry family sold the manor house and the bulk of the land to Samuel Taylor Suit in 1888. The property had numerous owners over the next few years until the manor house burned in 1895. Sumner Welles, Undersecretary of State during Franklin D. Roosevelt’s administration, purchased 245 acres of Oxon Hill Manor in 1927 and built a large house approximately one-third of a mile from the ruins of the colonial dwelling. The Maryland-National Capital Park and Planning Commission, Department of Parks and Recreation now owns the extant mansion and 55 acres of the original tract.

The Oxon Hill Manor collection is an excellent resource for studying changes in plantation lifeways over a 180-year period and documenting the long-term occupation by multiple generations of families. First occupied in the years when Chesapeake society had shifted to a slave economy, Oxon Hill has the potential to provide insights into 18th- and 19th-century economic and social patterns in Maryland. This assemblage is significant not only for the diagnostic ceramics, glass, and metal artifacts recovered, but also for the wide range of organic material found in an 18th-century well, including leather, cloth, and wooden objects.

Archaeological Investigations

Several archaeological projects were conducted at Oxon Hill Manor between 1980 and 1986. Terrence W. Epperson of the Maryland Geological Survey first identified Oxon Hill Manor (18PR175) as an archaeological site in 1980 as part of the initial planning process for the Maryland Route 210/Interstate 95 interchange. Shovel test pits were dug at 30-meter intervals within the proposed highway right-of-way, but the soil was not screened. Epperson discovered that the foundation of the manor house and extensive artifact deposits were located directly within the proposed highway alignment. He also observed and recorded the location of the nearby Addison family cemetery (18PR176) and the Addison Mausoleum (18PR177).

Richard J. Dent directed an additional Phase I survey of Oxon Hill Manor for the Laboratory of Archeology at the University of Maryland at College Park between July and November 1981. This investigation included both pedestrian surveys and subsurface testing in the highway right-of-way and an assessment of the Addison cemetery and mausoleum. Dent then established a grid over the entire project area and dug 626 shovel test pits at 5-meter intervals. All soil was screened, and all artifacts were retained. A geologist’s probe was then used to test for structural remains and artifact concentrations at three-meter intervals along 36 lines radiating from the dwelling foundation. In addition, Dent excavated 18 one-meter-square test units at discretionary locations. These units were excavated in 10cm levels, and all soil was screened. The archaeologists also uncovered approximately a third of the Oxon Hill manor house foundation, including all four corners and most of the south wall, to determine the nature of construction techniques and the completeness of the feature. Due to the finds at Oxon Hill Manor, the Maryland State Highway Administration proposed an alternate realignment of the highway to avoid the foundation of the house.

Silas Hurry of the Maryland Geological Survey conducted a Phase II excavation in the new alignment in the fall of 1983 and winter of 1984. This investigation was limited to the western half of the area that Dent surveyed in 1981, focusing on an area adjacent to the manor house where a retaining wall was proposed. Archaeologists conducted a ground reconnaissance of the site, established a new grid related to the current highway center line, and used Dent’s sampling strategy to define five activity areas, designated Areas I through V. Thirty-one one-meter-square test units in Areas I-IV and 28 shovel test pits in Areas IV and V were excavated. All test units were excavated following natural strata. Soil was screened through ¼-inch mesh, and all cultural material was retained. Hurry’s investigation revealed significant intact subsurface features, such as a well, post holes, and planting beds.

Silas Hurry and Maureen Kavanagh of the Maryland Geological Survey conducted additional Phase II surveys in the eastern portion of the impact area in the fall of 1984. A total of 729 systematic shovel test pits were excavated at 10-meter intervals, 5-meter intervals, and 2.5-meter intervals to provide additional information on artifact distributions and soil anomalies. All soil was screened through ¼-inch mesh. Based on concentrations of artifacts, soil anomalies, and above-grade features, 36 one-by-one-meter-square test units were then excavated and all soil was screened through ¼-inch mesh. This investigation revealed five areas of artifact concentrations, identified as Areas VIa-e, within the eastern section of the proposed highway right-of-way.

Garrow and Associates, Inc., under the direction of Patrick Garrow and Paul Brockington, undertook Phase III investigations of the northern half of Oxon Hill between January 3, 1985 and January 2, 1986 within the six areas delineated by the Maryland Geological Survey. Fieldwork consisted of a combination of block excavations and mechanical excavation using the grid established by Hurry. Excavation consisted of 223 screened and 185 unscreened one-by-one-meter units in Area I, 52 screened one-by-one-meter units in Area II, 72 screened and 13 unscreened one-by-one-meter units in Area IV, 11 screened and 14 unscreened one-by-one-meter units in Area V, 132 screened and 110 unscreened two-by-two-meter units from Area VIa, 144 screened two-by-two-meter units in Area VIb, 14 screened one-by-one-meter units in Area VIc, and six screened one-by-one-meter units in Area VId. Each unit was dug in natural layers, with soils either dry-screened through ¼-inch mesh or water screened. Soil from the two wells was completely water-screened. Backhoe trenching was used in Areas III and IV to expose buried deposits, while mechanical stripping was used in Area VIb. A total of 345 features were uncovered during this investigation, including two wells, two cellars, one foundation, post holes, post molds, trenches, and planting holes. All artifacts were retained with the exception of cobbles, roofing slate, glazed and unglazed bricks, mortar, and oyster shell from non-feature contexts, which were weighed and discarded in the field. Soil samples for flotation were also taken from each level at the southeast corner of every unit.

In 1986, John Milner Associates, Inc. conducted a Phase II survey of the southern section of 18PR175, including the manor house and associated outbuildings, located in the PortAmerica Development immediately adjacent to the highway right-of-way. Archaeologists excavated 487 shovel test pits at 10m intervals over the approximately 82 acres associated with the plantation. Additional shovel test pits were dug at 5m intervals when artifacts were recovered. Fifty-one one-by-one-meter test units were then excavated. All soil from the shovel test pits and test units were screened through ¼-inch mesh, and all artifacts were retained. Soil samples were also collected for analysis. This survey identified 16 site areas and subareas of archaeological resources associated with the plantation. In addition, several backhoe trenches were excavated to the west of the manor house to determine the structure of the garden terrace. Archaeologists also included an intensive survey of the manor house foundations and nearby two outbuildings. Twenty-one one-by-one-meter excavation units were excavated, including six within the house’s interior. All soil was screened through ¼-inch mesh and all artifacts were retained.

In 1988, Milner conducted a Phase III excavation of the remainder of 18PR175 for the PortAmerica Development. A report on the excavations is currently being written and the artifacts were transferred to the Maryland Archaeological Conservation Laboratory in the summer of 2003. The materials excavated by Milner will be included in this project at a future date.


A total of 307,254 artifacts were uncovered from the investigations at Oxon Hill Manor between 1980 and 1986 by the Maryland Geological Survey, University of Maryland, and Garrow and Associates. A wide range of materials was uncovered, ranging in date from the prehistoric period through the mid-20th century, including metals, tobacco pipes, ceramics, and hundreds of small finds.

Vessel analysis and reconstruction of ceramics were conducted for Area I, Area I Well, and Area VI. Ceramics range in date from the early 18th century through the 20th century in various vessel forms, such as milk pans, teapots, bowls, and pitchers. A wide variety of ceramic types were identified at Oxon Hill, including North Devon, tin-glazed earthenware, Staffordshire slipware, Red Sandy earthenware, Buckley ware, Whieldon ware, creamware, pearlware, Rhenish blue and gray, English brown and English dry-bodied stonewares, Chinese porcelain, and English soft paste porcelain. Examples of white clay, red clay, stoneware, and reeded stems are included in the 5,237 tobacco pipe fragments recovered from the site.

Glass fragments were also analyzed and reconstructed into vessels for Area I, Area I Well, and Area VI. Over 86,000 container glass fragments represented numerous case bottles, wine bottles, pharmaceutical bottles, spirit bottles, and a demijohn. Fifty-six wine bottle fragments were scratched with the letter "A", the name "Addison", an "A" over the date "1726", or the phrase "J[]A", although only one unidentified bottle seal was recovered. Over 2,000 tableglass fragments representing a wide variety of forms, including bowls, tumblers, water glasses, stemware, wine glasses, pitchers, a decanter, a cruet, a salver, and a plate were recovered. Stemware included examples with both balustered and drawn stems. In addition, 24 beads of various colors and seven mirror fragments were recovered.

Agricultural items recovered from Oxon Hill include 14 hoes, iron spade fragments, and an iron hedge shear, while stable-related artifacts include 44 horseshoes, 32 harness parts, five bosses, two harness buckles, and one bridle fragment. One hundred and eighty-three gunflints, four shot, three unidentified gun parts, two side plates, one flintlock, and one gun barrel constitute the arms-related artifacts. Objects associated with sewing include 29 straight pins, five thimbles, and five scissors fragments, while 300 buttons, 57 buckles, 11 jewelry parts, and eight hook & eyes represent objects related to clothing. Architectural and furniture objects include 106 tacks, 26 locking mechanism fragments, seven keys, and six drawer pulls. Other artifacts include 19 coins, 15 meat hooks, 10 toy fragments, five slate pencils, and two lead bale seals.

A total of 42,179 faunal remains were recovered from the Oxon Hill well, including 38,191 bones and 3,327 shell fragments. No analysis has been conducted on the faunal materials from the site, but the assemblage contains fish, reptile, and mammal remains. Worked faunal materials include 41 dominos, 20 shell buttons, 17 bone buttons, 10 toothbrushes, six ivory hand fan fragments, six unidentified bone fragments, four beads, two bone handles, one ivory piano key, one pearl, one horn utensil handle, and one bone comb.

Exceptional preservation of organic remains from a well discovered in Area I provides additional clues to activities occurring at Oxon Hill Manor during the 18th century. Wooden artifacts include 56 bottle corks, utensil handle fragments, bowls, buttons, musical instrument fragments, tobacco sticks, a fan mount and a scrub brush. Leather shoe components for women, men, and children, leather saddle fragments, and wool and silk textile fragments were also found. The recovery of over 24,000 seeds in addition to the animal bones reveal important dietary information about the inhabitants of Oxon Hill during the 18th century.


All records from the Phase II investigations at 18PR175, along with those from the Garrow and Associates Phase III excavations, are originals, and are in fair condition except for some minor tears and field stains. They are archived separately from the John Milner Associates Phase III documents.

The Phase II excavations resulted in 66 excavation units designated by south and east coordinates. Field records include excavation unit reports, feature forms, plans, profiles and cross sections, soil descriptions, and feature interpretations. Field note journals exist for both Phase II projects. Miscellaneous documents include correspondence, background information, report graphics, artifact information, lot number notes, field bag progress logs, miscellaneous maps, a proposed highway plan, catalog sheets for the report, an executive summary with notes, artifact catalogs, Phase III proposals and mitigation estimates, and report notes. Separate reports were prepared for each of the Phase II projects. These have been scanned as .PDF files and are word searchable. Phase II documents are housed in three letter-sized clamshell boxes, three oversized archival folders, two archival enclosures, and one oversized roll.

The Garrow and Associates Phase III excavation was divided into six main areas, comprising approximately 750 numbered excavation units and several hundred potential features. These numbers are approximate, as many of the features were renamed, combined, or deleted throughout the course of the investigation. Excavation records include square-level summary forms, square-level forms, plans, profiles, and feature forms. Feature forms for specific areas are placed in folders sequentially in groups of five. There are 17 daily field journals, kept by a variety of crew leaders and members. Miscellaneous documents include unit lists; miscellaneous feature notes; minimum vessel counts; miscellaneous historic artifact counts, analysis, and distribution documents; prehistoric artifact lists and analysis; conservation and curation notes; elevation tables; photo logs; flotation logs; survey notebooks; bag inventories; miscellaneous maps; soil and floral analysis; historian reports; historic inventories; project work plans; technical proposals, permits, and contracts; lot number notes; and catalogs. The Phase III collection also contains a lab report, an Oxon Hill history draft, and the final report in two volumes. These have been scanned as .PDF files and are word searchable.

Records from the John Milner Associates Phase III excavations (known internally within the MAC Lab as the Addison Collection, to distinguish it from the Phase II and Garrow Phase III materials, called the Oxon Hill Collection) are housed in twenty-three letter-sized archival clamshells, one legal-sized clamshell, and seven document rolls. All documents are original and in good condition, with minimal dirt and staining.

Excavation records include unit records, feature records, unit summaries, plan drawings, and profile drawings. The site was excavated by area and given numeric designations. The excavation records have been organized first according to area and then sequentially by unit number; feature records are included in the folder of the unit in which they were encountered, with the exception of features 6, 329, and 407, which comprise the large cellar and have been given their own folders. There are is a small grouping of excavation documents with no assigned area.

Field journals have been organized according to author, year, and volume. These are available online as .PDF documents but are not searchable. Other records in the collection that are also available as .PDFs include artifact analysis, ecofact analysis, maps, plan and profile drawings, background research, catalogues, photography logs, field logs, and Harris matrices, and multiple weekly, status, and interim reports.

Photographs taken on-site or in post-processing for all the investigations at 18PR175 are available through the online database, and are searchable. Researchers should note that images are not linked directly to specific documents, and photo records do not necessarily exist for all features or units. Original images consist of slides, negatives, prints, and contact sheets. All records are housed at the MAC Lab.


Dent, Richard J., Karen L. Orrence, Jonathan Wright, Gloria Judges, and Anne Dilorenzo
1983     Final Report on the Preliminary Site Examination (Intensive Reconnaissance) of the Oxon Hill Manor Project Area Interstate Route 95/Maryland Route 210 and Interstate 295 Interchange Modification Project. Report prepared for the Envirodyne Engineers of Baltimore, Maryland and the Maryland State Highway Administration.
Garrow, Patrick H. and Thomas R. Wheaton, Jr., eds
1986     Final Report, Oxon Hill Manor, Archaeological Site Mitigation Project, I-95/MD 210/I-295. Vols. 1 and 2. Report prepared for the Maryland Department of Transportation, by Garrow and Associates, Inc.
Hurry, Silas D.
1984     Intensive Archeological Testing of the Oxon Hill Manor Site. Report prepared for the Maryland State Highway Administration. Maryland Geological Survey File Report Number 187.
Hurry, Silas D. and Maureen Kavanagh
1985     Additional Intensive Archeological Testing at the Oxon Hill Manor Site: An 18th Through 19th Century Plantation in Maryland. Report prepared for Maryland State Highway Administration. Maryland Geological Survey File Report Number 189.
McCarthy, John P., Jeanne A. Ward, George D. Cress, and Charles D. Cheek
1989     Intensive Archeological Survey of the Addison Plantation Site and Intensive Archeological Testing of the Addison Manor Foundations, Beltway Parcel, Portamerica Development, Oxon Hill, Prince George’s County, Maryland. Report prepared for James T. Lewis Enterprises, Ltd. by John Milner Associates, Inc.
McCarthy, John P., Jeffrey B. Snyder, and Billy R. Roulette, Jr.
1991     Arms from Addison Plantation and the Maryland Militia on the Potomac Frontier. Historical Archaeology (25)1: 66-79.

Digital Resources



Archaeological Report
Artifact Documents
Conservation Documents
Excavation Documents
Faunal Analysis
Feature Forms
Field Notes
Harris Matrix
Historical Research
Lot Index
Mapping Data
Photo Log
Project Documents
Soil Documents
Specialized Analysis
Survey Logs


  • No images


Browse Artifacts

Thank you for visiting our web site. If you have any questions, comments,
or new information to share, please contact us at patricia.samford@maryland.gov.

An online archive of over 30 archaeological sites in Maryland, produced by the Maryland Archaeological Conservation Lab with the support of the National Endowment of the Humanities.