At the junction where the Warrenton Turnpike turned west from Braddock Road, the Union army marched from Centreville to meet Confederate forces in the first great battle of the Civil War on July 21, 1861, and that afternoon Union soldiers passed the site again while fleeing from the Manassas battlefield to reach Washington, D.C., the next day. The Old Stone Church was used as a Union hospital by Assistant Surgeon David L. Magruder, who later wrote that he took possession of the stone church in a grove of timber to the right of the road the army had followed in advancing to the attack. The many casualties treated there and in nearby hospitals overwhelmed the Federal medical service, which was poorly organized, short of ambulances, and lacked trained personnel. The church served again as a Union hospital during the Second Battle of Manassas in August 1862. Both armies used these roads and occupied the area several times during the war. Soldiers later dismantled the church, but it was rebuilt in 1870. South of the church stood the largest fort in the Confederate defensive network around Centreville, and nearby camps housed 40,000 Confederate soldiers in log huts during the winter of 1861–1862. Private Frank Thompson of the 2nd Michigan Infantry served there as a nurse after the 1861 battle; Thompson was actually Sarah Emma Edmonds, one of hundreds of women who adopted male dress to take part in the war, later recounted her experiences in Nurse and Spy in the Union Army, and received a pension for her service.
