He was born in 1816/17. [sources: date: 2 (44 in 1861), 4 (44 in 1861)]
He enlisted and was mustered into service on 19 November 1861. He enlisted at Philadelphia, Pennsylvania. He was mustered in as a private, at Philadelphia, Pennsylvania. He was a private in company B. [sources: 1, 2, 3, 4]
He is listed on the company muster-in roll dated 3 December 1861. [source: 4]
He deserted, apparently before 31 December 1861, since he's listed as deserted on the company muster roll dated from 7 October to 31 December 1861. [source: 4]
He was not on the muster-out roll when the regiment mustered out. [sources: 1, 2]
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) (John Biddle)
2 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 27 June 2004 (John Biddel; muster-in roll has 'Isaac Biddel')
3 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (Isaac Biddle)
4 compiled service record, co. B, 91 Pennsylvania Inf. (Isaac Biddle)