These earthworks are a portion the original fortifications which made up Fort Lincoln. This fort was built during the summer of 1861 to serve as an outer defense of the city of Washington. It was named in honor of President Lincoln by general order no. 18, A.G.O., Sept 30, 1861. The brigade of major general Joseph Hooker was the first to occupy this area. In immediate command of this fort was captain T. S. Paddock. The Civil War cannons have been placed here through the courtesy of the Department of Defense to commemorate this auspiscious occasion.
Ben Jacobson (Kranar Drogin), CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons