The Aaron Sheely Farm became the headquarters for General Marsena Patrick, in 1863 who was provost marshal for the Army of the Potomac. He was responsible for the care and transportation of all prisoners, wagon trains and hospital guards. All Confederates left behind were prisoners of war. They were guarded on the Aaron Sheely farm and the injured soldiers were cared for there. This famous farm and land served not only as the prisoner of war camp but also as General Patrick’s headquarters. To be near the prisoners he stayed at the barn.

On July 2nd, General Patrick finished interviewing “a great many Prisoners.” he then moved forward in Gettysburg where he formed a central depot for Rebel captives. This depot was somewhere within Union lines and south of Gettysburg, possibly along or adjacent to the Baltimore Pike.