He was born in 1835/36 (2 (25 in 1861)).
When he enlisted, he was living in Philadelphia, Pennsylvania (2).
He enlisted and was mustered into service, at Philadelphia, Pennsylvania, on 27 November 1861 (1, 2 [16 Dec 61]). He was mustered in as a private, in company B (1, 2, 3-4).
He deserted on 7 January 1862 (1). (According to (2), he was mustered out on 27 November 1861!) He was a private, in company B (3-4).
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 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 29 June 2004 (William Yerkes)
3 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (William Yerkees)
4 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (William Yerkes)