Fort Greble was an American Civil War-era Union fortification constructed as part of the defenses of Washington, D.C. during that war. Named for First Lieutenant John Trout Greble, the first West Point graduate killed in the U.S. Civil War, it protected the junction of the Anacostia and Potomac rivers, and from its position on a bluff in the Congress Heights, precluded any bombardment of the Washington Navy Yard and southeastern portions of the city. It was supported by Fort Carroll to the northeast and Fort Foote to the south. It never fired a shot during the war, and after a brief stint as a U.S. Army Signal Corps training facility, was abandoned and the land returned to its natural state. As of July 2007, the site of the fort is a community park. Planning and construction Prior to the outbreak of war, Congress Heights (so called because the Capitol building in downtown Washington could be seen from the tops of the hills) were owned by the Berry family, who also owned much of the Anacostia River bottomland to the west of the Heights. In the days following the First Battle of Bull Run, panicked efforts by the Union were made to defend Washington from what was perceived as an imminent Confederate attack. These makeshift entrenchments were largely confined to the direct approaches to Washington and the bridges that spanned the Potomac. Multiple forts were constructed in the Arlington region to the southwest of Washington on land rented or leased from the pre-war owners. Despite these efforts, following General George B. McClellan assuming command of the Military Division of the Potomac on July 26, 1861, he found that In the wake of his declaration, fort construction was accelerated and expanded, with new strong points and artillery positions springing up around the entire 37-mile (60-km) perimeter of the District of Columbia. In order to prevent an attack on the undefended Maryland side of the Potomac, Brigadier General John G. Barnard, chief engineer of the Department of Washington, directed that several forts be constructed on the Congress Heights in order to protect the Navy Yard and Washington Arsenal from bombardment. At the crucial western end of the Heights would be the then-unnamed Fort Greble. Planning and surveying for the proposed line of forts progressed quickly, and by the end of September 1861, work had begun on what was to become Fort Greble. Under