He was 43 years old when he enlisted (3 [46 in 1863, 43]). He was born in Chester, Pennsylvania (3, 7 [Philadelphia PA]).
He was a basket maker (3, 7). He was living in Philadelphia when he was enrolled (7).
He was 5 feet 5-3/4 inches tall, had a light complexion, blue eyes, and grey hair (3, 7 [5'6"]).
He was enrolled and mustered into service as a private in company K on 22 October 1861, at Philadelphia, Pennsylvania (1, 7).
He was transferred on 24 December 1861 to company E (1, 7, 9).
He fought at the battle of Gettysburg (4).
On 6 October 1863, he returned from hospital (5).
On 27 October 1863, he was detailed as cattle guard (6).
He re-enlisted for three years as a veteran volunteer, at Bealton Virginia, on 24 December 1863 (1, 3). He was enlisted by Lieutenant Carpenter, and mustered into service by Lieutenant Swann (3, 7 [26 Dec]).
He was killed in action on 12 May 1864 at Spottsylvania Court House, Virginia (Laurel Hill), by being shot in the head while charging the enemy's works (1, 2, 3, 7, 8, 10).
On 26 January 1865, company E published resolutions mourning his death (and fifteen others), and sympathizing with their families (11).
On 30 August 1864, his widow, Ann Riley, successfully applied for a pension (12, 13).
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 list of deaths, company E
3 descriptive roll, company E, entry 97
4 Pennsylvania Memorial, 91st Pennsylvania plaque, Gettysburg, Pennsylvania (Thos D Riley)
5 consolidated morning report, 91st PA, 6 October 1863 (Pri Riley)
6 consolidated morning report, 91st PA, 27 October 1863 (Priv Riley)
7 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 6 May 2004 (Thomas D Riley)
8 consolidated morning report, 91st Pennsylvania, 9 June 1864 (Thos D Riley)
9 company K, list of men transferred, #19 (Thomas D Riley)
10 'The Ninety-first Pennsylvania volunteers', Philadelphia Inquirer 8 June 1864 page 3 (Thomas D Riely [sic])
11 'Headquarters company E', Philadelphia Inquirer 26 January 1865 page 5 (Thomas Riley)
12 pension index, by name (Thomas D Riley)
13 pension index, by regiment (Thomas D Riley)
[I did not find an entry for him in the index on <www.ancestry.com> to the 1890 veteran's census (searched May 2007)--but some had no identifying information]