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Meeting at Headquarters: Public Archeology at Valley Forge

Stone house.

Washington's Headquarters.

One of the primary destinations for visitors to Valley Forge National Historical Park is the modest stone house that served as General George Washington’s Headquarters during the Revolutionary War winter encampment of 1777-1778. Arriving at the encampment grounds in December, General Washington had planned on being “hutted” in a small log cabin, just as his soldiers were. It soon became apparent, however, that the work of administering an army of roughly ten thousand men required more space than a simple log hut provided, especially as the British army was just a few miles away in Philadelphia, the capital city of the fledgling American nation.

The General chose the Isaac Potts house, located in a defensible position at the confluence of Valley Creek and the Schuylkill River, as the base of his operations that winter. From here, he and his officers set about the task of molding the Continental Army into a fighting force that was capable of taking on one of the world’s most powerful armies. Washington lived and worked in this house for the six months of the encampment and was joined there by his wife in February of 1778. Although serving as a military headquarters, this house was also a home, and it is the domestic activities that took place there during the encampment about which our research is perhaps the most revealing.

Following the departure of the Continental Army from Valley Forge in June 1778, the Potts house reverted to its former role as a rural home. The Valley Forge Centennial and Memorial Association acquired the property in 1878 to commemorate the one-hundredth anniversary of the encampment. Their acquisition of the house paved the way for what was to become Valley Forge NHP, and prevented any major modifications to the structure itself. In 1893, the Valley Forge Park Commission was created, and maintained the house as part of a state park until it was transferred to the NPS in 1977.

Previous Excavations

The area around Washington’s Headquarters was first investigated in 1973 as part of a larger archeological effort being conducted at, then, Valley Forge State Park. The excavations were carried out under the direction of Vance Packard, Jr. of the Pennsylvania Historical and Museum Commission. The 1973 excavations revealed foundations for two 19th century structures behind the headquarters- an early to mid-19th century frame addition to the building, and a reconstruction of an encampment-period cabin which incorporated part of an earlier foundation. A stone-lined well and portions of a buried ground surface were identified (later designated Horizon D), although no clearly encampment-period features associated with the ground surface were recognized.

The site was investigated again in 1986 during the course of a drainage swale installation project. A shallow swale was excavated in an area behind the headquarters building to alleviate a drainage problem in this location, and artifact deposits were uncovered by the earth-moving equipment used to construct the swale. Work ceased, and park archeologists recorded the exposed deposits and features, collected numerous artifacts, and closely monitored the remainder of the drainage swale installation. Potentially significant features noted included portions of the stone foundation walls revealed by the 1973 excavations. Many encampment-period artifacts were recovered. Significantly, a concentration of late 18th century artifacts was noted in an area of dark soil matrix (Feature 1). The cultural deposits were not excavated, but their locations were carefully mapped. Prior to backfilling of the area, the exposed deposits were covered with plastic sheeting to facilitate relocation, in the event of future archeological excavations in this location.

The 2009 Field Season

Exposed archeological unit.

Excavation near Washington's headquaters showing foundations and stone-lined well.

In 2006, the author and Dr. David Orr, park archeologist at the time of the 1986 work, re-examined the artifact assemblage and data from the drainage swale installation project. We saw that Feature 1 was most likely an 18th century feature, potentially dating to the encampment period, and therefore to General Washington’s occupation of the Potts house. The buried ground surface noted in the 1973 excavations (and referred to as Horizon D when exposed in 1986) possibly represented a relatively undisturbed 18th century ground surface. We also thought that the stone foundations in this area were worthy of being examined more closely for evidence that they may be related to an encampment-period structure.

In 2009, Washington’s Headquarters was to be re-opened following a series of repairs and renovations, and this provided the perfect opportunity to not only gather significant archeological data, but to do so in a manner which would be highly visible to park visitors. The author, along with fellow graduate students Carin Bloom and Katie Cavallo from Temple University were hired by the park to conduct the excavations. Dave Orr returned to the site as an advisor to the project through the NPS Volunteers in Parks program.

A top priority was to excavate Feature 1, identified during the 1986 excavation, which was likely an encampment-period feature. We also wanted to expose the buried ground surface represented by Horizon D to determine if it contained evidence of General Washington’s occupation of the house. Additionally, we wished to search for evidence of a dining cabin that Washington had built during his stay to give himself and his officers and aides additional meeting space beyond that which was available in the relatively small Potts house.

The dining cabin is mentioned briefly in a letter from Martha Washington to her friend Mercy Otis Warren, whom she tells:

“…the Generals appartment is very small; he has had a log cabben built to dine in which has made our quarter much more tolarable than they were at first.” [sic]

No evidence of this cabin was seen in 1973 or 1986. However, the area immediately behind the headquarters was considered to be a likely site for this structure, and that any preserved 18th century ground surfaces present in this area may hold clues to its actual location.

Excavation Results

The 2009 excavation block was laid out behind the headquarters building in the area where the 1986 investigations had taken place. Our excavations in this area not only uncovered the features identified during that project, but revealed the densest concentration of features yet found at the Washington’s Headquarters site. The archeological deposits investigated in 2009 yielded a great deal of information about the site from all periods of its occupation, from prehistoric times through its use as an historic site within the park.

Foundation Walls

The 2009 excavations located two stone foundation walls, portions of which had been seen in the 1973 and 1986 excavations. Two separate and non-contemporaneous structures are represented by these walls. The foundations originally supported a frame addition to the rear of the headquarters building constructed sometime in the early to mid-19th century. This addition was removed in the late 1880s, and the Valley Forge Centennial and Memorial Association built a reconstruction of the encampment-period log dining cabin in its place, incorporating the western portion of the earlier foundation.

Dry-laid Stone Foundation

A small section of dry laid stone was also identified. This small line of stones runs perpendicular to the main foundation walls. It is likely that this represents a lightly-built foundation or sleeper wall for a porch on the north end of the mid-19th century frame addition, as the 1880s log cabin does not appear to have had any such appending structures.

18th Century Well

A stone-lined well that had been excavated in 1973 was re-exposed so that it could be drawn and photographed within the context of the other features, particularly the foundation walls. The well had been excavated to the water table, which is currently just over 20 feet beneath the present surface. The well is located entirely within, and partially incorporated by, the foundation walls, and thus clearly predates their construction.

As a well of this depth was not likely to go dry and be abandoned, this was probably the only well on the site prior to the construction of the 19th century frame addition. This well represents an original 18th century feature and dates to the time of construction of the Potts house or shortly thereafter, and provided water for Washington’s household.

Refuse Pits

Ceramic, metal, and bone artifacts.

Eighteenth-century ceramics, buckle, and bone knife handle.

Perhaps the most significant features revealed by the 2009 excavations were two refuse pits, both of which are securely dated to the last quarter of the 18th century, and at least one of which was almost certainly in use during General Washington’s occupation of the Potts house. Feature 1, originally identified in 1986 as a concentration of late 18th century artifacts located within a dark soil matrix was revealed to be a potentially encampment-period pit. The majority of the ceramics from this feature can be dated to the mid to late-18th century and include redware, creamware, and some white salt-glazed stonewares.

The other 18th century pit (Feature 16) contained exclusively 18th century objects, with the majority being typical of the Revolutionary period. Artifacts included tin-glazed earthenware, creamware, Whieldon ware, and a pistol grip bone knife handle. One certain encampment period object recovered from this feature was a brass “double D” buckle which is typical of Revolutionary War period military suspensory hardware of the type used with a knapsack, cartridge box, or sword rig. The presence of this object indicates that the Feature 16 trash pit was almost certainly in use during General Washington’s occupation of the Potts house. Feature 16 also contained a great abundance of animal bone; analysis of this bone has great potential to inform us about the food consumption patterns of high-ranking officers at the Valley Forge encampment.

The 18th Century Ground Surface

A buried plow zone dating to the 18th century was uncovered during the excavations. Archeologists recognize buried ground surfaces by color and texture. Over time, the top layer of soil in an archeological site accumulates much organic material from dead plants, burning events, and other cultural activities, as well as through natural processes. When buried by other soils, these old surfaces can still be recognized by their darker color and artifact inclusions. The action of plowing, especially with shallow 18th century plows, cuts through the dark surface layer and into the lighter colored subsoil below, leaving long, parallel streaks, or “plow scars” where some of the darker colored surface soil has filled the gouges made in the subsoil by the plow. The top layer of soil that has been disturbed by plowing activity is called the “plow zone.”

Plow scars at the subsoil interface were nearly perpendicular to the orientation of the headquarters building, indicating that the plowing pre-dated the construction of the Potts house. The plow zone contained exclusively 18th century and prehistoric artifacts. The upper portion of the plow zone contained a great deal of charcoal representing broadcast discard of hearth sweepings, indicating that the plow zone itself had not been truncated by later disturbance.

Prehistoric objects recovered from this level included several projectile points. Three are triangular forms typical of the Late Woodland period (ca. A.D. 1000 – European contact). One stemmed point recovered is typical of the Late Archaic period (ca. 3000 – 1000 B.C.), as is a quartzite preform suggestive of the broadspears common during the latter portion of that period. Two sherds of Late Woodland pottery were recovered which likely date between A.D. 1200 and 1550. The density of prehistoric artifacts in general, and diagnostic Late Woodland artifacts in particular, indicates that the landscape immediately surrounding Washington’s Headquarters was an area of intensive Native American activity, and possibly the location of a late prehistoric village.

Public Archeology at Valley Forge NHP

Archeologist and volunteer excavate.

Archeologist and volunteer excavate site at Valley Forge.

Washington’s Headquarters is the focal point of Valley Forge NHP. It is the one place in the park that visitors make sure they see before leaving. We talked with thousands of people during the course of the 2009 excavation, often hundreds over the course of a single day. We worked on Saturdays in order to be on site for the park’s busiest day of the week.

Visitors were thrilled not only to visit an active archeological site, but to interact with the archeologists, ask questions, and even handle the artifacts. People often came by in the morning and watched us work, toured the rest of the park, and then returned before leaving the park to see if any new discoveries had been made.

The excavations allowed us to make the site more than just a show-and-tell for visitors, but to teach them about some of the fundamental aspects of archeological methodology. Few visitors left without seeing at least one object actually come out of the ground. The preserved ground surface beneath a series of fills allowed us to give lessons on stratigraphy, and the refuse pits served as excellent examples of how archeologists identify and excavate features. Late 19th century pipe trenches provided opportunities to talk to visitors about things like intrusive features, site formation processes, and how to separate deposits from different time periods in complex sites.

In addition to the archeological experience we were able to offer visitors while they were at the site we maintained a weekly web-log about the progress of the excavations, which allowed visitors to keep up with the project even after they returned home. We used the blog as a teaching tool, and each week’s entry used some aspect of what we had done that week as a brief lesson in archeology. For example, the exposure of large sections of the buried early ground surface became a simplified stratigraphy lesson for those reading the blog.

Nearly 90 volunteers worked on the project, both in the field and in the lab, and altogether they contributed over 1,000 hours of work. The volunteer effort was such a success that we had to limit the amount of time individual people could work in a given week so that we could accommodate others who wanted to help. Were it not for all of our fantastic volunteers, we obviously would not have been able to accomplish as much as we did. Like the many park visitors who came to the site, these folks had a unique opportunity to experience archeology in action, and left with a greater appreciation for how archeologists recover and preserve the past.


One of the greatest tools an archeologist or preservationist can have at their disposal is an informed public. People who understand what archeologists do are more likely to appreciate and support archeological research. Sites like Washington’s Headquarters offer many opportunities for public outreach to show people what archeologists do and why research is critical to preserving our history and, blogs are a simple and effective way to reach the public and are an underutilized resource for archeology and historic preservation.

It is largely because of the success of the public component of this year’s work at Washington’s Headquarters that the NPS has approved another field season at the site in 2010. Our focus for this coming summer will be to extend the excavations to the south to trace the buried 18th century surface. Although no indications of the encampment-period dining cabin were identified in the 2009 field season, we now believe that the most likely location of the hut lies just to the south of our excavation block. The presence of the preserved surface makes this a likely place to find this and other features, including those relating to the prehistoric component at the site. Our public effort will continue, refined and improved by lessons learned this year. We hope that our work will serve as an example of how one of the most effective preservation strategies at our disposal is also one of the easiest to implement- simply reaching out to the public, whose history we ultimately seek to preserve.

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By Joseph R. Blondino, Temple University