Thanks. The references from the OR that you cite are nearly all that is known about that unit of ex-Union POWs who fought at Egypt Station. Their recruiter was John G. O'Neill who in Sept 1864 was promoted to colonel of the 10th Tennessee. In October he received orders through General Hood to proceed to Millen, Ga., and recruit POWs to be used to reinforce Bates's division. O'Neill stayed on in Georgia and recruited POWs at Andersonville in Jan and Feb 1865.

Best wishes,
John Lundstrom