Fort Daniel: A geophysical survey of an 1813 Georgia frontier fort

Submitted by Dr. Sheldon Skaggs and Dr. James D’Angelo (sheldonskaggs@georgiasouthern.edu)

The search for the exact location of Fort Daniel began in the summer of 2007 when the Gwinnett Archaeological Research Society (GARS), under the direction of Dr. James D’Angelo, embarked on a project that had the potential to add significantly to Gwinnett County, and Georgia history. The project revolved around a frontier fort, known later as Fort Daniel, that tradition placed on a ridge-top knoll on Hog Mountain in Gwinnett County. While there had been a historical roadside marker on the highway for many years, there had never been any physical proof of exactly where the fort was located. Additionally, if the site of Fort Daniel was there, what would remain of the fort after a century and a half of agricultural development in the area? Pending sale of the property for commercial development added a keen sense of urgency to locating and documenting what archaeological evidence remained.

According to 1813 Divisional Orders from Major General Allen Daniel, commander of the 4th Division of the Georgia Militia, to Brigadier General Frederick Beall, “for the security of the frontier settlement” General Beall was to replace an already existing fort with a new one “sufficient for the reception of two hundred men.” Construction orders included sinking “substantial timbers” that would reach ten or eleven feet above the surface, three feet into the earth. Besides giving good information on how the fort was constructed, this letter, found by a GARS member in the State archives, indicated that there was an earlier fort at the site, something that had not been known before.

Dr. D’Angelo and Dr. Skaggs created a research design that included two forms of subsurface remote sensing, metal detection (MD) and ground penetrating radar (GPR), that would help determine if the site was at that location, and something about the nature of what was there. Local metal detecting volunteers used a variety of different machines, while the initial GPR used a GSSI SIR 2000 connected to a 400 mhz antenna. Later surveys used a Mala X3M connected to a 500 mhz antenna and a GEM Systems GSM19GW gradiometer.

Before remote sensing was carried out, a roughly 200’x200′ area was cleared of brush and thickets and then, using a Contractor’s Transit and compass, was gridded into 80 20’x20′ grid units laid out using the west property line as a baseline. The southwest corner of each grid unit was marked with a wood stake and labeled as to its provenience. Metal finds were then recorded by grid locations. This grid system was also used in laying out subsequent ground penetrating radar and gradiometer surveys in later years.

2011 Ft Daniel research 01

Metal detection survey grid of Fort Daniel area. Dotted lines show 2007 GPR survey area, solid lines show 2010-2011 GPR and magnetic gradiometer survey area.

Results from the metal detection survey were particularly encouraging with numerous hand wrought nails (dated between 1735 and 1790) and early machine-cut nails (dated to 1810’s by examining a number of diagnostic features) along with lead shot and other military items. The GPR survey also suggested potential locations for fort features.

2011 Ft Daniel research 02 artifacts

Nails, shot, and button from Fort Daniel metal detection survey.

The initial assumptions about the fort location, confirmed as much as possible by remote sensing, where tested by exposing three areas with a mechanical excavator. Two areas turned out to be important; the central fire pit of a southwest blockhouse and a segment of the eastern wall thought at first to be a possible latrine ditch. Subsequent excavations were done by hand and further defined the nature of the blockhouse fire pit and where the blockhouse intersected the southern and western walls. Finally, evidence was found for both southeast and northwest wall corners. As it worked out, the fort dimensions were 28% smaller than a frontier fort plan sent to the Georgia Governor by Secretary of War, Henry Knox, in 1794. This plan, discovered at the Georgia State Archives, came to light after the basic footprint of Fort Daniel had been determined. The blockhouses at Fort Daniel are on opposite corners from the ones in the Knox plan.

2011 Ft Daniel research 03 ft knox plan

Fort plans suggested to Georgia Governor Matthews in 1794. Redrafted from Military Affairs, Vol. 2, Part 1, 1793-1800, pg. 166, by William Field.

The bottom of the stockade wall trench, assumed at the planning stages to be a feature up to 36 inches deep, actually turned out to be 32 inches below the surface directly below about 6-12 inches of plow zone. The question then arose again about the likelihood that any shallower (interior fort) features surviving agricultural development. Additional GPR surveys were conducted along with a magnetic gradient survey to try and answer this question.

2011 Ft Daniel research 04 color GPR

Composite ground penetrating radar survey maps of 2007and 2010 compared to 28% reduced Knox plan. Walls of fort are oriented north/south and east/west while the grid offset from north/south. Red areas have the highest radar reflections, dark blue areas have the lowest radar reflections.

2011 Ft Daniel research 05 gradiometer

Gradiometer map of Fort Daniel area compared to 28% reduced Knox plan. Walls of fort are oriented north/south and east/west while the grid offset from north/south. Red areas have the highest positive magnetic gradient, white areas the lowest negative magnetic gradient.

The most important achievement of the second series of geophysical surveys is the clear definition of the remainder of the exterior wall trenches, reducing the need for excavation to just areas around the potential gates and the northeast blockhouse. Strong anomalies in the GPR survey at potential interior wall lines and corners suggest that the Knox plan for the interior buildings of the fort may have been was followed as well, and that at least some of the northwest building features may remain. The gradiometer readings in particular are very promising, with the most complex and highest positive readings overlapping closely the position of a potential soldier’s barracks on Knox’s plan.

The Fort Daniel site is located on private land that was under contract for commercial development when the site was first brought to the attention of Dr. D’Angelo. While his organization had hoped to preserve the site for posterity, the possibility of development had forced another, less desirable, option: a hurried rescue excavation of the entire site. But with the collapse of the real estate market in general, the group will now be able to concentrate on their original goal: to create an historic site and archaeological research park to serve the local community well into the future. The geophysical surveys show where targeted excavation might be placed at future educational events to find interior features. Finally, it is safe to say that Fort Daniel has been located, and that we now have a fairly clear idea of the fort’s dimensions and footprint.

GARS and the Foundation are indebted to the owner of the property on which the site is located, Mrs. Ann Grant, for her graciousness in allowing us to conduct this research in her “back yard.”

Note about the authors: James D’Angelo is Archaeological Advisor to the Gwinnett Archaeological Research Society (GARS) and Principal Investigator at the Fort Daniel site in Gwinnett County where GARS has been investigating since the fall of 2007. Sheldon Skaggs was a graduate student at the University of Georgia during the first GPR survey in 2007, and is now a Temporary Assistant Professor of Geology at Georgia Southern University.

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