He was born on 2 August 1835 (10; 4 (25 in 1861), 10 [79 yrs 2 mos 26 ds at death]). He was born in County Tyrone, Ireland (4, 10). He was born to John Cook and Eliza Irwin (10).
When he enlisted, he was a farmer (4).
When he enlisted, he was 6 feet 3 inches tall, and had a dark complexion, dark eyes, and dark hair (4).
He enlisted and was mustered into service on 20 November 1861 (1, 4). He was enlisted for three years, at Philadelphia, Pennsylvania, by Captain Gilbert (4). He was a private in company G (1, 11).
He was transferred on 4 December 1861 to company A (1, 6).
He was discharged on surgeon's certificate of disability, at Franklin Barracks, on 4 March 1862 (1) or 25 March 1862 (3) or 24 March 1862 (4). He was a private in company A (1, 3, 11).
He may be the William Cook of company K [?] whom Lentz reported on 9 July 1864 the regiment had heard was discharged (2).
In 1890, he was living in Guthrieville, East Brandywine, Chester County, Pennsylvania (8). He had broken bones "in both limbs" (8).
He applied successfully from Pennsylvania for a pension on 13 July 1891 (5, 7, 9).
He again applied for a pension on 26 February 1907 (5, 9).
He died of senility on 28 October 1914, at 5224 Addison Street, 46th ward, Philadelphia, Pennsylvania (5, 9, 10). On 31 October 1914, he was buried at Hopewell Cemetery, Downington, [Chester County], Pennsylvania (10).
Margaret Cook, his widow, applied successfully from Pennsylvania on 3 November 1914 for a pension (5, 7, 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)
2 letter, Lentz to Bennett, 9 July 1864
3 Register of men discharged, co.A (William Cook)
4 company A descriptive roll, entry 76 (William Cook)
5 pension index, by regiment (William Cook)
6 company G, register of men transferred (William Cook)
7 pension index, by name (William Cook)
8 1890 US census, veterans' schedule, Pennsylvania, Chester County, East Brandywine, supervisor's district 2, enumeration district 93, page 2, lines 14 and 24 [line 24 seems more reliable] (Wm Cook)
9 pension index, by regiment, 91st PA Infantry, company G (William Cook)
10 death certificate, Philadelphia, Pennsylvania, 28 October 1914, #25179 (William Cook)
11 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (William Cook)