Bates has two Thomas Tully's enlisted on the same day, one in company E, and another in company I, who was not on the muster-out roll. I have assumed he initially enlisted in company I and was transferred to company E.
He was 21 years old when he enlisted (2 [24 in 63], 8 [21 (co.I), 23 (co.E)]). He was born in Philadelphia, Pennsylvania (2, 8).
He was a printer (2, 8). He was living in Philadelphia when he was enrolled (8).
He was 5 feet 8-1/4 inches tall, had a dark complexion, grey eyes, and dark hair (2, 8 [5'8"]).
He was enrolled and mustered into service in company I on 25 October 1861, at Philadelphia, Pennsylvania (1, 8). He was transferred to company E (see above note). He served as a private (1).
He was accidentally wounded in the hand at Washington DC, and lost his finger (2).
He fought in the battle of Gettysburg (4).
On 2 October 1863, he returned from being detailed as a cattle guard (7).
He re-enlisted for three years as a veteran volunteer, at Bealton Virginia, on 24 December 1863 (1, 2, 8). He was enlisted by Lieutenant Carpenter, and mustered into service by Lieutenant Swann (2).
On 8 June 1864, he was detailed by Major Lentz for duty in the division hospital (5, 6 [22 Jun]). He was still detailed as a nurse in September (?) 1864 (6).
He mustered out on 10 July 1865 with his company (1).
He applied successfully for a pension on 21 December 1870 (3, 9, 10).
On 11 October 1879, his widow, Elizabeth V Tully, successfully applied for a pension (9, 11).
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 descriptive book, company E, entry 94 (Thomas Tully)
3 Veterans' administration. Pension index, by name. (Searched 21 Jan 2001, on <www.ancestry.com>.) (Thomas Tully)
4 Pennsylvania Memorial, 91st Pennsylvania plaque, Gettysburg, Pennsylvania (Thomas Tully)
5 special order 43, HQ 91st PA, 8 June 1864
6 [list of detailed men, probably from Sept 1864] (Thomas Tully)
7 consolidated morning report, 91st PA, 2 Oct 1863 (Tully)
8 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 6 May 2004 (Thomas Tully)
9 pension index, by regiment, 91st PA Infantry, company E (Thomas Tully)
10 pension index, by name (Thomas Tully)
11 pension index, by name (Elizabeth V Tully)
[I did not find an entry for him in Ancestry's index to the 1890 veterans' census (searched 5 June 2009)]