ETERNALSOLDIER
Archaeology at Fort Mifflin:
Deeper Dig
Our research design centers three zones of field investigation: ground truthing of geophysics in the Parade Ground to identify a suspected shaft feature, examination of the interior and exterior of the East Sally Port, and field study adjacent to the Old Magazine and the southwest Kitchen Building of the Officer’s Barracks.
With this project, we add to the story of the site from its beginnings through World War II, a long record of material and historical change, a record of Philadelphia in microcosm.
Originally designed and erected in stone by the British in a star-shaped plan in 1771-72, and hastily completed in wood by Americans in 1777, George Washington personally visited Fort Mifflin in the Summer of 1777 demonstrating its importance to the rebel defense of the Delaware Valley:
“I have planned a method of throwing a Garrison into Fort Mifflin, if it succeeds and they with the Assistance of the Ships and Gallies should keep the obstructions in the River, General Howe’s Situation in Philada will not be the most agreeable, for if his supplies can be stopped by Water it may be easily done by land. To do both shall be my utmost endeavour, and I am not yet without hope that the acquisition of Philada may, instead of his good fortune, prove his Ruin.”
From George Washington to John Hancock, 23 September 1777, Founders Online, National Archives
In Washington’s overall strategy, Fort Mifflin was essential fortification blocking the Royal Navy from resupplying Crown Forces then occupying Philadelphia. The great Siege of Fort Mifflin began at 730am on November 10, 1777; 400 American soldiers (White, Black, Native American) held off more than 2,000 British troops and 5 naval warships for 5 days until it was evacuated on November 15. 245 were killed and wounded.
The site was almost completely leveled by incessant bombardment of thousands of cannonballs from British ships, and by fires set by retreating Americans. Post Revolution, Fort Mifflin entered a long period of episodic rebuilding and abandonment lasting a further 150 years. It served as a prison for Confederate soldiers during the Civil War and housed the 76th Coastal Anti-Aircraft Artillery Battalion during WWII, the first coastal antiaircraft regiment of Black soldiers.
Fort Mifflin has received multiple historic designations, being designated in 1969 among the National Register of Historic Places and in 1970 as a National Historic Landmark.
Max Brown and Eric Hubbard set out with survey antenna to lay in the excavation trenches
Planes fly low into Philly Int'l
Public Day 2025
Max Brown and Eric Hubbard set out with survey antenna to lay in the excavation trenches
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Geophysics - Parade Ground 2025
The areas in black are the remnants of a walkway that encircles the eastern half of the Parade Ground. This network of brick, slate and granite paving is reported in a number of documents. Ground Penetrating Radar displays the features of the brick, slate and granite paving closest to the surface.
Geophysics - Shaft Feature
Just west of the Commandant’s House (constructed 1796), we see a circular feature visible through multiple levels of the geophysics. Archival research has revealed this may be a shaft feature such as a well or privy (Cotter et al. 1993: 260), pinpointing this zone for our program of excavation and retrieval of macrobot.
Geophysics - Old Magazine
In the upper left we also see the foundations of the “Old Magazine” erected in 1798, demolished 1867. These remains were partially excavated by Campbell 1959 and lie adjacent to the southwest Kitchen Building of the Officers’ Barracks. This area contained destruction debris and artifacts that Campbell associated with the fiery Siege of Fort Mifflin.
Soldier's Garden - Archaeobotany
Archival research uncovered evidence of a post-Revolution Soldiers’ Garden. A map of Fort Mifflin produced in 1807 illustrates the gardens to have been positioned along the eastern walls of the fort. Researchers from Penn Museum CAAM sampled this area in accordance with our overall plan to gather archaeobotanical data of the garrisons’ diet and health.
Fort Mifflin Excavation History
To bring together the results of earlier minor test pits and piecemeal excavations into a comprehensive narrative, Eric Hubbard of Penn CAAM created a digitized map that illustrates the record of archaeological research at Fort Mifflin, a first for the site. Excavations from 1959, test pits from 1969, and rescue projects in 1978 and 2007 comprise the bulk of available data. In addition, archeological monitoring projects were carried out in 1993 and 1996 as infrastructure was updated at the site. Our current excavation areas are in green.
