An Irish immergrate Capt. Keogh was General John Buford's, (of Gettysburg fame), closest aide. Keogh, distraught at Buford's death, requested a transfer to be appointed to Gen. Stoneman's staff. Keogh became Stoneman's aide-de-camp. During a raid planned for Macon, Georgia and the Andersonville Confederate prison camp designed by Stoneman to free captives there, They were both captured on July 31, 1864. Keogh and Stoneman’s command were surrounded during the Battle of Sunshine Church, Georgia. They were captured after both their horses were shot out from under them. Stoneman suffered the distinction of being the highest-ranking officer that the Confederates captured during the war. Both were held for over two months as prisoners of war before being specially exchanged at General William T. Sherman's request that fall, Stoneman being exchanged for Confederate Brigadier General Daniel C. Govan.