Established in 1861 to guard the approaches to Benning's Bridge across the Anacostia River. The fort was irregular in shape with nine sides and a perimeter of 354 yards mounting 22 guns. Structures included a guard house, two barracks, officer's quarters and a mess house. Outworks included Battery Mahan
A 17 May 1864 report from the Union Inspector of Artillery noted the following: "Fort Mahan.–Garrison, one company Unattached Heavy Massachusetts Artillery–1 ordnance- sergeant. Armament, three 12-pounder field guns, four 15-inch Rodman, four 24-pounder F. D. howitzers, two 8-inch siege howitzers, one Coehorn mortar, one 10-inch siege mortar, three 30-pounder Parrotts. Magazines, two; dry and in good order. Ammunition, full supply and serviceable. Implements, complete and serviceable."
Abandoned in 1865 at the end of the war.
Current Status
Fort Mahan Park in Northeast Washington DC. Some overgrown remains of the earthworks, several markers.
Cooling, Benjamin F. III and Owen, Valton H. II, Mr. Lincoln's Forts: A Guide to the Civil War Defenses of Washington, Scarecrow Press, 2009, ISBN 0810863073, ISBN 9780810863071, 334 pages.
Roberts, Robert B., Encyclopedia of Historic Forts: The Military, Pioneer, and Trading Posts of the United States, Macmillan, New York, 1988, 10th printing, ISBN 0-02-926880-X, page 137.
