Fort Thayer (1861-1865) - A Union U.S. Civil War Fort established in 1861 in Northeast Washington DC. Named Fort Thayer after Colonel Sylvanius Thayer, (Cullum 33), expert engineer known as the father of the United States Military Academy. Abandoned in 1865 at the end of the war.
Established in 1861 as a lunette with a perimeter of 180 yards and emplacements for eight guns. Fort Thayer was situated between Fort Saratoga and Fort Lincoln in the defensive ring around Washington DC.
A 17 May 1864 report from the Union Inspector of Artillery noted the following: "Fort Thayer, Capt. H. D. Scott commanding. – Garrison, withdrawn; works guarded by Sixteenth Massachusetts Battery, from Camp Barry–1 ordnance-sergeant. Armament, four 24-pounder barbette, one 24-pounder siege, two 8-inch siege howitzers, one 24-pounder Coehorn mortar. Magazines, one: dry and in good order. Ammunition, full supply, well packed and in good order. Implements, complete and serviceable."
The fort was abandoned in 1865 at the end of the war.
No remains, no markers. Sources differ on the location, some located in the fort in the wrong quadrant of the city (Roberts) and others clearly outside the fort ring perimeter (GNIS). The topography indicates the probable location is at the end of Thayer St. NE between 24th St. NE and 25th St. NE and Irving St. NE and this agrees with the location described in North American Forts listing.