Fort Mercer was built and
Fort Mifflin were rebuilt and garrisoned to protect a line of
chevaux de frise obstacles across the
Delaware River.
Fort Billingsport was built downriver to protect another line of these obstacles. Fort Mercer had earthen walls with a surrounding ditch, topped with a log palisade. The fort was about long and wide and mounted 14 cannons, with
bastions on the landward corners. A separate outer redoubt was located north of the fort, but this was not garrisoned. The fort could accommodate a garrison of 1,500 men, but only 600 were available, mostly
Rhode Island troops of the
Continental Army commanded by
Colonel Christopher Greene, also a Rhode Islander. French officer
Thomas Duplessis made the fort more defensible by the small garrison by having a wall built inside the river side of the fort. The British abandoned Fort Mercer as they evacuated Philadelphia on June 18, 1778. The
Patriots retook the site and rebuilt the fort, manning it until 1781, when the fighting moved to
Yorktown, Virginia, culminating in an American victory and leading to the cessation of hostilities. ==Gallery==