He was born in 1820/21 (8 (40 in 1861)).
He enlisted and was mustered into service on 17 September 1861 (1, 8). He enlisted at Philadelphia, Pennsylvania (8). He was mustered in as a private, at Philadelphia, Pennsylvania (8). He was a private in company I (1, 11, 12).
On 19 March 1863, he returned to the regiment from brigade headquarters (5).
According to Bates, he was discharged on 25 April 1863 (1, 8). Since the Pennsylvania Archives card claims he was discharged because his term had expired, this seems unlikely (8).
On 16 March 1864, he returned from being absent sick (7).
On 15 April 1864, he was one of seven men in the regimental pioneer corps (2).
On 4 July 1864, he was detailed for duty in the pioneer corps at brigade headquarters (3, 4, 6). He was still there in September (?) 1864 (6).
On 3 November 1864, he was reported discharged because his term had expired (9). He was a private, in company I (11, 12).
1 Bates, Samuel Penniman. History of Pennsylvania volunteers, 1861-5. Harrisburg: B. Singerly, state printer, 1869-71. 5 volumes. 'Ninety-first regiment', volume 3, pages 186-233. (In the roster)
2 general order 8, HQ 91st PA, 15 April 1864 (Patrick Costello)
3 letter, Sellers to Bennett, 4 July 1864
4 special order 61, HQ 91st PA, 4 July 1864 (Patrick Costello)
5 consolidated morning report, 91st PA, 19 March 1863 (Pri Costello)
6 [list of detailed men, probably from Sept 1864] (Patrick Costello)
7 consolidated morning report, 16 March 1864 (Priv Costello)
8 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 4 September 2004 (Patrick Costello)
9 company I, register of deaths (Patrick Costello) [his name is crossed out]
10 consolidated morning report, 91st Pennsylvania, 3 November 1864 (Pvt Costello)
11 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (Patrick Castello)
12 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (Patrick Costello)