He was 32 years old when he was enlisted (8). He was 35 years old when he was reenlisted (9). He was born in Antrim [?], Ireland (8 [Antroro?], 9).
When he enlisted, he was a labor[er] (8, 9).
He may be the brother of William McCoy (see the 1910 census for William).
He was 5 feet 11-1/2 inches tall, and had a dark complexion, blue eyes, and dark hair (8, 9).
He was enlisted and mustered into service on 14 October 1861 (1, 8). He was enlisted for three years, at Philadelphia, Pennsylvania, by Captain Sinex (8). He was mustered in service by Captain Sinex (8). He initially served as a private in company F (1).
He was transferred on 4 December 1861 to company D (1, 10).
He fought at the Battle of Gettysburg (12).
Beginning 13 August 1863, he was under arrest (5). On 3 September 1863, a general court martial ordered him sentenced to lose $10 per month of his pay for 3 months, and to carry a 30-pound log for 6 hours a day for 30 days, without being excused from his other duties (2). He was still reported under arrest on 5 September 1863, but not on 6 September 1863 (6, 7).
He reenlisted as a veteran volunteer on 26 December 1863 (1, 9). He was enlisted for three years, at Bealton, Virginia, by Lieutenant Swan (9).
On 15 April 1864, he was one of seven men in the regimental pioneer corps (3). He was probably still there in September (?) 1864 (4).
On 3 August 1864, he was a brigade pioneer (11).
He mustered out on 10 July 1865 with his company (1).
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 special order 72, HQ 91st PA, 3 September 1863
3 general order 8, HQ 91st PA, 15 April 1864
4 [list of detailed men, probably from Sept 1864] (John McCoy [?]; can't read date of detail)
5 consolidated morning report, 91st PA, 13 August 1863 (John McCoy)
6 consolidated morning report, 91st PA, 5 September 1863 (not named)
7 consolidated morning report, 91st PA, 6 September 1863 (not named)
8 company D, descriptive roll, entry 16 (John McCoy)
9 company D, second descriptive roll, entry 46 (John McCoy)
10 company F, register of men transferred (John McKay)
11 consolidated morning report, 91st Pennsylvania, 3 August 1864 (John McCoy)
12 Pennsylvania Memorial, Gettysburg, Pennsylvania (John McCoy)