In October 1864, John G. O'Neill, colonel of the "10th Tennessee Regiment (Irish Volunteers)", was authorized to recruit Union prisoners at Andersonville and Millen, Georgia, to replenish the depleted ranks of the regiment. O'Neill, recovering from wounds received at the Battle of Resaca, appears to have delegated part of the task to a newly appointed lieutenant colonel, Michael Burke. In October and November 1864 O'Neill and Burke enlisted more than 250 soldiers of a number of Union regiments. Efforts were made at first to recruit Irish immigrants in compliance with Seddon's original instructions, but when few complied, native-born Union soldiers were enlisted. The recruits were required to take an oath of allegiance to the Confederacy, and were not issued arms or ammunition until the night before their first engagement.