Ground Truth: Recent Investigations of Ground Penetrating Radar Anomalies by the MHT Archaeological Research Program

By Dr. Zachary Singer (MHT Research Archaeologist)

The theme for Maryland Archeology Month 2022 is “The Future of Studying the Past: Innovative Technologies in Maryland Archeology”. One suite of innovative technologies that is being highlighted is remote sensing: methods which allow archaeologists to detect cultural resources buried beneath the ground surface. Remote sensing technologies have transformed how archaeologists study the past. Today, with the aid of high precision GPS receivers and Geographic Information Systems (GIS) mapping software, the coordinates of potential archaeological resources can be precisely located via remote sensing, recorded and plotted in GIS, and then surgically examined through excavations pinpointed to their exact locations.

Over the years, the MHT Office of Archaeology had dabbled with these technologies, carrying out some limited survey with magnetic susceptibility technologies or partnering with others for such work. Beginning in 2019, MHT Chief Archaeologist, Matt McKnight, began a push to acquire additional equipment with which to undertake a more rigourous terrestrial remote sensing research program. The remote sensing technologies deployed by our office include a magnetic susceptibility meter (MagSusc), a fluxgate gradiometer, and a ground penetrating radar (GPR) system. We also utilize a high-precision GPS system capable of pinpointing a location on the Earth’s Surface accurate to within 7 millimeters (or about 1/4 inch).

MHT archaeologists have assisted with remote sensing surveys on archaeological sites throughout Maryland and identified many intriguing anomalies suggestive of archaeological features. However, as is always the case with remote sensing data, these potential features are just that: potential features. Without archaeological ground truthing through excavation it is not possible to conclude with absolute certainty what the various anomalies identified via remote sensing represent. Fortunately, our office has collaborated with many members of the Maryland archaeology community to ground truth (or physically excavate) some of the intriguing anomalies identified via our remote sensing surveys to determine their forms, functions, and ages. Below, we present a sampling of some of these exciting ground truthing results.

Barwick’s Ordinary (Caroline County)

MHT archaeologists carried out a geophysical remote sensing survey at the Barwick’s Ordinary Site on the Choptank River in Caroline County during the summers of 2019 and 2020 to examine a field where the owners of the property had encountered colonial artifacts during a prior landscaping project. The primary objectives of remote sensing at the site were to obtain detailed imaging of the subsurface features believed to be yielding the artifacts recovered on the property. Magnetic susceptibility, gradiometry, and GPR surveys on the property revealed several anomalies suggestive of buried architectural elements.

Annotated results of the MagSusc, Gradiometer, and GPR remote sensing surveys at Barwick’s
Ordinary.

In the fall of 2020, with assistance from ASM volunteers, locals, and Professor Julie Markin of Washington College, a few small test units were excavated to ground truth the anomalies at Barwick’s. The results confirm that the site contains well-preserved, artifact rich, mid-late 18th century archaeological features. Come participate in additional ground truthing excavations this summer at the Annual Tyler Bastian Field Session, which will take place at Barwick’s Ordinary from May 20-30, 2022.

Dr. Matt McKnight ground truthing a GPR anomaly, which was revealed to be the corner of a likely 18th-century privy at the Barwick’s Ordinary site.

Calverton (Calvert County)

In the summer of 2020, MHT archaeologists conducted a ground penetrating radar survey at the 17th-century Calverton Site in Calvert County in an area located within 10 meters of the eroding edge of Battle Creek. The creek is slowly destroying the site and the goal of the GPR survey was to identify anomalies in the portion of the site most at risk of loss from shoreline erosion. The GPR survey would later be investigated via ground truthing using traditional archaeological methods.

Annotated results of the GPR remote sensing survey at Calverton, highlighting the location of a shaft anomaly, which ground truthing determined to be a 17th-century
cellar (CLICK IMAGE TO EXPAND).

Seven likely anthropogenic features were identified in the GPR survey at Calverton. Eight test units were excavated by Applied Archaeology and History Associates during the summer of 2020 to assess these GPR anomalies. The excavations resulted in the identification of ten cultural features, which yielded late 17th- and early 18th-century artifacts including tobacco pipes, a Charles I sixpence coin (1639-1645), and sherds of tin-glazed earthenware. The largest and most artifact-dense feature related to the colonial occupation of Calverton was an in-filled cellar.

Photo of the 17th century cellar feature after it was bisected to ground truth the GPR
anomaly.

Maiden’s Choice (Washington County)

In the spring of 2021, MHT conducted a GPR survey at the Maiden’s Choice I site in Washington County to search for buried domestic structures. The GPR survey revealed the presence of an anomaly suggestive of a subsurface foundation remnant roughly 40 ft east-west by 20 ft north-south, and with an apparent chimney remnant (roughly 5 X 5 ft) near the center. In the fall of 2021, MHT collaborated with the Western Chapter of the Archeological Society of Maryland to excavate three test units to ground truth these GPR anomalies. The ground truthing excavations uncovered remnant rubble stone foundations with artifacts recovered from the plowzone dating primarily to the late 18th and early 19th centuries.

3D models of the excavation units that revealed the remains of a late 18th century
foundation.

Domestic artifacts were present such as furniture tacks, buttons, clay marbles, handwrought nails and coins including a 1776 Spanish half-reale, a pierced 1796 half dime, and a “draped bust” American half cent (1800-1808). A Napoleon Bonaparte First Consulate German jetton was also recovered. A jetton is a commemorative token or medal and this one likely dates to the years 1799-1804, before Napolean was coronated as Emperor. The fall 2021 excavations suggest that this site is a domestic site associated with the Barnes-Mason family that occupied the Maiden’s Choice property after 1773.

Fortunately, in the three examples discussed above, ground truthing of remote sensing anomalies resulted in the discovery of artifact rich archaeological features. However, this is not always the case. Remote sensing anomalies can also be caused by natural occurrences like bioturbation from plant roots and animal burrows. Accordingly, although it is tempting to jump straight from remote sensing results to archaeological site interpretation, the step of ground truthing cannot be skipped. Excavations will always be necessary to determine whether remote sensing anomalies are in fact the remains of
exciting archaeological features or less exciting gopher holes.

“Little Las Vegas” in Charles County

By Nicole A. Diehlmann 

Enjoy the following guest blog by Nicole A. Diehlmann, co-author of the new MHT Press publication on the architectural history of Charles County, In the Midst of These Plains: Charles County Buildings and Landscapes. 

Since 1920, major changes in Charles County’s economy, demographics, and physical development shifted it from a primarily agricultural economy to a bedroom community of Washington, D.C.  The legalization of gambling was one little-known feature of this shift.

The construction of Crain Highway (US 301) in the 1920s and the Potomac River Bridge in 1940 opened a major north–south transportation corridor, which linked Charles County to the larger urban centers of Baltimore, Washington, D.C., and points south. The new road brought an increase in automobile traffic and tourism, and restaurants and hotels began to spring up along the US 301 corridor. After the end of Prohibition in 1933, small taverns opened, which became popular places to have a drink or two and play slot machines. At that time, slot machines were widely regarded as innocent amusement, even though gambling was outlawed by the State of Maryland. 

In the early 1940s, many county residents questioned the legality of slot machines, and the status of gambling became a contentious community issue. A grand jury was charged with studying the presence of illegal slot machines throughout the county. The grand jury’s report stated that there was no evidence indicating that any slot machines were in operation in Charles County, but in reality, establishment owners had successfully hidden or removed them prior to inspections. Subsequent reports concluded that the problem lay in a lack of law enforcement and argued that since gambling was so pervasive, it might as well be legalized so that the county could collect money from licensing fees. A bill was introduced in the Maryland General Assembly in 1949 for legalization as a “local option” that would affect only Charles County. The bill outlined several benefits of legalization, including how revenue generated would be used to reduce real estate taxes, pay off school bonds, and provide support for the library fund, the fire department, and the hospital. On the momentous day of June 21, 1949, gambling was legalized in Charles County by a vote of nearly 2 to 1. 

The Waldorf Motel and Restaurant featured flashy neon signs intended to attract visitors to this popular site along the US 301 strip. Image source: Historic Site Files, Charles County Government.

People from surrounding areas had been coming to the county for years to play the slots, but legalization spurred an extraordinary number of tourists to visit and thus, growth in all sectors in order to support the influx. The combination of legalized gambling, transportation improvements, and postwar mobility combined to dramatically increase the volume of traffic passing through the area and transformed Waldorf, the northernmost county town on US 301, into a tourist destination. Crain Highway was widened to four lanes to accommodate the traffic. Between 1949 and 1968, along a fourteen-mile stretch of US 301, 21 hotels with a total of 600 rooms popped up alongside restaurants, gas stations, and entertainment facilities that accommodated tourists and gamblers. This concentration of restaurants and hotels, each with its own array of slot machines, turned the once sleepy village of Waldorf into a large center of commercial activity. The largest sites for gambling in Waldorf in the late 1950s were Club Waldorf Inc. with 140 slot machines and the Waldorf Restaurant with 60 machines. Other casinos were clustered along the Potomac River, including the Reno, off the shores of Colonial Beach, Virginia, with more than 300 machines, and Marshall Hall, across from Mount Vernon, with 193 machines. At the height of the gambling era, revenue from slot machine licensing fees provided a full quarter of the county’s income.  

Although located off the shore of Colonial Beach, Virginia, the Reno Casino was considered to be within the jurisdiction of Charles County, Maryland, because it was in the Potomac River, which is wholly in the state of Maryland. In this way, Virginians were given easy access to Maryland’s slot machines. Photo source: In the Midst of These Plains: Charles County Buildings and Landscapes. 

The slot machine era in Charles County was a time of extravagance, excitement, and growth. The slots were everywhere, and everyone—adults, children, residents, and tourists—played them. At first buildings intended for other commercial uses were adapted to accommodate slot machines, but eventually special structures were built as gambling and entertainment houses. The demand for construction continued to increase, so that by 1960 there were 57 restaurants along the highway, with the larger ones billing themselves as casinos. The neon lights on restaurants and hotels made the US 301 strip look like “Little Las Vegas,” as it came to be known. Many of the restaurants offered dancing and live bands, often attracting famous performers. 

The Wigwam, demolished in 2013, was one of the most notable of the casinos that lined US 301. In the later twentieth century, the building housed Walls Bakery. Image source: Historic Site Files, Charles County Government. 

In Charles County, most of the motels were constructed as fully integrated buildings under a single roof. The dominant styles were vernacular interpretations of Colonial Revival and Modernist styles, although Craftsman, Western, and Spanish Colonial Revival styles were present in motels in other jurisdictions. While they were often architecturally non-descript, motels and restaurants distinguished themselves by their roadside signage. Large neon signs dominated the grounds visually, enticing passing motorists to stop at the establishment. The Waldorf Motel, demolished in 2017, was an excellent example of the type, containing several rows of motel rooms, a large neon sign, and a two-story restaurant topped by a neon sign. One of the most notable of the casinos was the 1950 Wigwam. It included a casino building with an attached teepee, a decorative wooden totem pole, and a large Western-themed neon sign. After demolition in 2013, the neon sign was acquired by Charles County and now marks the entrance to the Indian Head Rail Trail on US 301 in White Plains. The extant Blue Jay Motel served African Americans who came to US 301 during the era of segregation. It was constructed by Arthur Farrar and featured in the Negro Traveler’s Green Book between 1959 and 1964.  

The Blue Jay Motel, constructed by Arthur Farrar, served African Americans who came to US 301 during the era of segregation. Image source: Historic Site Files, Charles County Government. 

In the late 1950s and early 1960s, the pervasiveness of slot machines began to worry many residents. A 1958 issue of Man’s Conquest magazine called Crain Highway the “301 sin-strip,” Charles County “dirty, drunken and debauched,” and accused residents of profiting from “slots, sex and sin.” Another magazine, Real Adventure, described the county as a “modern Sodom with thirty gin mills to the mile and a populace of gun-carrying gangsters and sleazy dames.” By 1961, Maryland had three times as many slots as the state of Nevada and they produced an average annual revenue of $13 million. Reformers in Charles County pushed their case to end gambling, and just as legalization had been a community-wide fight, so was its demise. Due to continuing pressure from many groups, in 1962 Governor J. Millard Tawes announced the establishment of a committee charged with creating procedures to remove slots from the county with the least possible harm. Beginning in July 1965, the slots were phased out slowly over a three-year period. On June 30, 1968, store and restaurant owners watched as the last of the machines were removed from their establishments, and the slot-machine era in Charles County came to an end. 

The White House Hotel is one of the few slot-machine era motels remaining in the county. Image source: National Park Service, Historic American Buildings Survey.  

After slot machines were banned, the area’s popularity as a travel destination quickly declined. The construction of the Chesapeake Bay Bridge in 1954 offered Washingtonians ready access to Maryland’s oceanside resorts, which caused the decline of riverside resorts and further drained the tourism trade from Southern Maryland. Today, few vestiges of Charles County’s slot-machine era survive. Most of the larger hotels and restaurants along US 301 have been demolished for new commercial developments that serve the rising number of suburban residents living in the county. A few motels exist at the southern end of US 301 in the county, including the former White House Motel and the Bel Alton Hotel. 

Learn more about Charles County’s “Little Las Vegas” in the book In the Midst of These Plains: Charles County Buildings and Landscapes, written by Cathy H. Thompson and Nicole A. Dielhmann. You can purchase a copy from the Historical Society of Charles County or from MHT press at https://mht.maryland.gov/home_mhtpress.shtml. 

A Curated Coin from Calvert County (Guest Blog)

By Kirsti Uunila, RPA, Calvert County Historic Preservation Planner

For the past two summers, MHT archeologists have partnered with the Archeological Society of Maryland (ASM) and Calvert County to investigate the Calverton Site on the shore of Battle Creek to search for what remains of the seventeenth century town. Calverton, also known as Battle Town, was the first seat of Calvert County government. Established around 1668, it was abandoned sometime after the court was relocated to Prince Frederick in 1724. The town site has been in agriculture ever since. Battle Creek has eroded the Calverton Site with an estimated loss of more than 50 meters of shoreline. Using a plat of the town drawn in 1682 (see map), archeologists concluded that some of the town is still on land, including the first home of Michael Taney and other buildings.

A 17th-century plat of Calverton geo-rectified to modern satellite imagery.

An area near the Taney house is believed to have been a dependency or outbuilding related to the dwelling. It contained numerous artifacts from the seventeenth and early eighteenth centuries. One was a large wine-bottle fragment bearing a broken seal with the initial ‘M’. Michael Taney’s, perhaps? Several small features were excavated in the dependency, including an apparent line of postholes. Two of these postholes were situated approximately three feet apart, suggesting the presence of a door. The most notable artifact found was on the edge of one of these postholes. It is a James I silver shilling with a mint mark indicating it was made in 1604. Since the town was not established until sixty years after that, the coin had had a long journey and was likely to have been a treasured object. In “archeologist speak” it had been “curated” by its owner well beyond the date it was minted. Its placement in a posthole that may have held a doorpost suggests a deliberate act, possibly to bring good fortune to the building and its inhabitants.

Colonial bottle glass seal with an “M” mark, possibly for Michael Taney.

The artifacts and records of the second season are being analyzed now and we hope to learn more about the people who lived, worked, and traded in the Colonial port town. Calvert County proposes continuing work at the site and will use ground-penetrating radar (GPR) this spring to locate cellars, hearths, and other features that may be in imminent danger of erosion, and to investigate more of the site.

Curated 1604 James I silver shilling recovered from the base of a burned post at Calverton.

What’s “Magical” About Maryland Archeology?

By Sara Rivers Cofield, Curator of Federal Collections, Maryland Archaeological Conservation Laboratory, Jefferson Patterson Park and Museum

When a committee of archeologists selected “The Magic and Mystery of Maryland Archeology” as the theme for the 2019 Maryland Archeology Month, they were not thinking about Harry Potter or pulling a rabbit out of a top hat. “Magic” in anthropological terms, is anything people do to try to influence the supernatural. That includes personified supernatural forces like gods, ghosts, and ancestral spirits, and impersonal supernatural forces like luck. Usually when people try to influence the supernatural there is a clear end in mind and a ritualized procedure to follow. When you pick a penny up and say, “find a penny, pick it up, and all day long you’ll have good luck,” an anthropologist would classify that as a “magic” ritual.

Archeologists Annette Cook and Alex Glass carefully excavate one quadrant of the kitchen cellar at Smith’s St. Leonard.

Archeology is a sub-discipline of anthropology in the U.S., so we use the anthropological definition of magic for select artifacts that were once considered objects of power. There is a joke of sorts in archeology that any artifact of unknown purpose must be “ritual,” which is really code for “I have no other explanation.” That joke was born out of legitimate criticism, but it has scared some people away from considering ritual and magic in archeology. The burden of proof that something is “magic” is very high. However, it is a disservice to our understanding of past belief systems if we fail to consider possible ritual and magic uses of artifacts, especially if the context calls for it.

The Smith’s St. Leonard horseshoe was found in the fill of a kitchen cellar that contained debris from a remodeling episode associated with the brick hearth.

A perfect example is a well-worn horseshoe from Jefferson Patterson Park and Museum’s public archeology site, the Smith’s St. Leonard plantation, which was occupied ca. 1711-1754. The obvious default interpretation of a horseshoe is that it was for shoeing a horse, especially if the horseshoe is worn enough to show it was used. However, historical records indicate that it was rare to shoe horses in Maryland prior to the 1750s because the soft clay soils did not require it. Over 200 units have been excavated at the site, resulting in over 450 boxes of artifacts from the main house, a kitchen, a laundry, at least three slave quarter buildings, a store house, and a stable. Only one horseshoe was found, and it was not near the stable, but in a kitchen cellar that was filled with debris from a hearth remodeling episode.

Horseshoes have a long history as objects placed on thresholds, near hearths, or in ritual concealments to ward off evil or bring good luck. Furthermore, some of these beliefs hold that found horseshoes, such as those thrown from a hoof along a roadway, were the ones with power. For example, witches could not pass through a threshold guarded by an old horseshoe until they had traveled all the roads the horse had traveled, and by then it would be daylight. Thus, history and context suggest that the Smith’s St. Leonard horseshoe was a magical object that once protected the hearth.

The Smith’s St. Leonard horseshoe after conservation treatment.

It is not always possible to determine whether an everyday object was put to a magical purpose, and that is where the “mystery” of the “Magic and Mystery” theme comes in. There are many finds that might be evidence of magic, but there is no way to know with certainty. It is still worthwhile to consider the possibility though because it calls for an understanding of how the people who used these artifacts viewed the world. Ultimately, having that knowledge of how people in the past thought and behaved is what archeology is all about.

Interested in participating in excavations at Smith’s St. Leonard? The 2019 Public Archaeology program runs from May 7 to June 29. For more information visit http://www.jefpat.org/publicarchaeology.html.

Introducing Map-Based Medusa: Viewing Maryland’s Historic Places in Real Time

By Gregory Brown, Cultural Resource Information Manager

To kick off Preservation Month this May, the Maryland Historical Trust is pleased to announce a new interactive map-based tool, “map-based Medusa,” to explore the state’s inventory of historic places and archeological sites.  Taking advantage of new web-based mapping technology, map-based Medusa offers the opportunity to view Maryland’s extensive geographic database of historic and cultural properties and to access the records linked to these resources, all within an easily accessible user friendly interface.

The new system allows both in-house and remote access to the documentation of over 60,000 architectural and archeological resources in a variety of ways. Consultants and staff can view a proposed project area and see all known cultural resources, with links to Maryland Inventory of Historic Properties forms, National Register nominations, determinations of eligibility, and other detailed documents. Map-based Medusa also allows you to look up a property by name, address or inventory number, and view that property on a map along with associated forms and photos.

Most architectural information is freely available in Medusa. Archeological site location is restricted to qualified archeological professionals as mandated in the state’s Access to Site Location Policy. Any qualified professional can apply for a Medusa account to get access. For assistance using map-based Medusa, tutorials and FAQs are available online. We will introduce webinars and introductory videos in the coming months.

The new map-based Medusa application was created with the technical assistance of the Applications Development team of the Maryland Department of Planning, the Maryland Historical Trust’s parent agency. We are grateful for the efforts of Information Services Manager Ted Cozmo, Doug Lyford, Greg Schuster, and Debbie Czerwinski, building on earlier database development work of Maureen Kavanagh, Carmen Swann and Jennifer Falkinburg. The online version of Medusa was supported in part through a Preserve America grant administered by the National Park Service, Department of Interior, and by funding from the Maryland State Highway Administration through its Transportation Enhancement Program.

To start using map-based Medusa, go to https://mht.maryland.gov/secure/medusa/.

For more information, please contact Gregory Brown, Cultural Resource Information Manager, at gregory.brown@maryland.gov.

Interpretation at Sotterley Plantation: The Road to Relevance

By Jeanne Pirtle, Education Director, Historic Sotterley, Inc.

Historic Sotterley Plantation has a long history, to be sure. It has also been open to the public as a museum since 1960.  Let’s see, what was happening in the 1960’s? Schools were still segregated. Jim Crow was still alive.  And in St. Mary’s County, Maryland, Sotterley’s last private owner had decided to open Sotterley and create a non-profit so that it could be preserved.  As with most house museums at that time, the early tours focused on the furnishings and lives of the owners with a little legend, lore and myth mixed in.  After the owner’s death in 1993, ownership went to the Sotterley Foundation, which is now Historic Sotterley, Inc.