Fort O'Rourke Fair Haven. No visible remains of the fort can be found. Fort O'Rourke Fort O'Rourke is a former Union Army installation now located in the Belle Haven area of Fairfax County in the U.S. state of Virginia. It was the southernmost fort built to defend Washington, D.C. in the American Civil War. Following the surrender of Fort Sumter in Charleston, South Carolina, on April 14, 1861, President Abraham Lincoln declared that "an insurrection existed," and called for 75,000 troops to be called up to quash the rebellion. The move sparked resentment in many other southern states, which promptly moved to
1st U.S. Light Artillery, Battery E Corps, to May 1863. 2nd Regular Brigade, Artillery Reserve, Army of the Potomac, to June 1863. 2nd Brigade, Horse Artillery, Artillery Reserve, Army of the Potomac, to June 1864. 3rd Brigade, DeRussy's Division, XXII Corps, to July 1864. 1st Brigade, DeRussy's Division, XXII Corps, to October 1865. Defense of Fort Sumter, Charleston Harbor, April 12-13, 1861. Evacuation of Fort Sumter April 13. Reached Fort Hamilton, N.Y. Harbor, April 19. Moved to Chambersburg, Pa., June 3. Ordered to Washington, D.C., August 26, 1861. Duty at the federal arsenal and at Camp Duncan, defenses of Washington, until March 1862. Moved to the