Fort Mahan

Historical marker location:

4000 Benning Road Northeast, Mahaning Heights, District of Columbia

( Marker is at the intersection of Benning Road Northeast and 41st Street Northeast, on the right when traveling west on Benning Road Northeast.)

Civil War Defenses of Washington

The city was built on a swamp: The area that is now Washington, D.C. was originally a swampy, marshy region along the Potomac River. The construction of the city involved extensive drainage and landfill projects to make the land suitable for building.