According to the pension index cards, he enlisted under the alias William Campbell (7, 10). I assume he enlisted in the 192nd Pennsylvania Infantry under that alias.
He was born in Philadelphia, Pennsylvania (6, 7 [Ireland], 8 [Ireland], 11 [Ireland]). He was 20 years old when he was enlisted (6, 8 [44 in ?1884], 11 [44 in ?1884]).
He was a laborer when he was enlisted (6).
He was 5 feet 7 inches tall, and had a light complexion, gray eyes, and red hair (6).
He was enlisted and mustered into service on 18 October 1861 (1, 6, 12). He was enlisted for three years, at Philadelphia, Pennsylvania, by Captain Lentz (6). He served as a private in company F (1).
On 19 April 1863, he was sent to the corps hospital (2).
He deserted on 20 or 25 July 1862 (4, 6 [20 Jul]). He returned to duty on 18 August 1862 (4, 6).
He was transferred on 30 September 1863 to the Veterans' Reserve Corps (1, 3, 5, 6, 10, 12). He served for 25 months in the 91st (8, 11). He served in the 37th company of the 2nd battalion of the Veterans' Reserve Corps (12).
He also served in company A of the 192nd Pennsylvania Infantry (7, 10, 12). He served for 13 months (7, 8).
On 27 August 1877, he applied successfully for a pension (10, 12).
On 2 August 1884, he was admitted to the National Home for Disabled Volunteer Soldiers (7, 8, 11). He was admitted from Pennsylvania (8, 11). He was not receiving a pension (8). He had a gunshot wound in the left hand (8 [p.316 has 'head' [sic], 11).
In 1885, he was living in the Central Branch of the National Home for Disabled Volunteer Soldiers (7). He received no pension (7). He had a wound in his left hand (7). He was 45 years old (7).
He was discharged from the home on 16 March 1885 (7).
He was present in the Central Branch of the National Home in 1889 (8).
He was discharged from the Central Branch on 24 June 1890 (11).
On 7 April 1908, he again applied for a pension (12).
His application for readmission to the National Soldiers Home was denied, apparently in 1892-1893 (9).
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) (William Findley)
2 consolidated morning report, 91st PA, 24 April 1863 (Private Finley)
3 consolidated morning report, 91st PA, 29 Oct 1863 (Pri Findlay)
4 company F, register of deserters, #22 (William Findley)
5 company F, register of men transferred (William Findley)
6 company F, descriptive roll, #57 (William Finnley)
7 National Home for Disabled Volunteer Soldiers. Report of Managers of the National Home for Disabled Volunteer Soldiers, transmitting the report of the said board for the year ending June 30, 1885. January 7, 1886. Serial Set volume 2415, session volume 10, 49th Congress, 1st Session, House Miscellaneous Document 38, page 173 (William Campbell alias Findley)
8 Letter from the President of the Board of Managers of the National Home for Disabled Volunteer Soldiers, transmitting the report of the Board for the fiscal year 1889. Serial Set volume 2768, session volume 9, 51st Congress, 1st Session. House Miscellaneous Document 77. Pages 312, 316. (William Finley)
9 Report of the Board of Managers of the National Home for Disabled Volunteer Soldiers for the fiscal year ended June 30, 1893. Serial Set volume 3151, session volume 1, 53rd Congress, 1st Session. House Miscellaneous Document 35. Page 167. (William Finley)
10 pension index, by name (William Campbell, alias William Findley)
11 Report of the Board of Managers of the National Home for Disabled Volunteer Soldiers for the fiscal year ending June 30, 1890. Serial Set volume 2869, session volume 1, 51st Congress, 2nd Session. House Miscellaneous Document 38] (William Findlay)
12 pension index, by regiment, 91st PA Infantry, company F (and second card) (William Findlay alias William Campbell)
[I did not find an entry for him in the index on <www.ancestry.com> to the 1890 veteran's census (searched May 2007)]