He was 19 years old when he was enlisted (3).
He was enlisted and mustered into service on 20 or 30 September 1861 (1 [co.D: 20 Sep, co.H: 30 Sep], 3 [1 Oct]). He served as a private (1).
He was transferred from company H to company D (3).
On 14 or 16 October 1861, he was discharged at Philadelphia, Pennsylvania, on writ of habeas corpus, because he was a minor (1 [14 Oct], 2 [16 Oct], 3 [14 Oct], 4, 5 [no date]).
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) (James H Cathcart)
2 company D, register of men discharged, entry 14 (John Cacheart [sic])
3 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 8 Aug 2004 (John H Cathcart; roll also has 'James Catheart')
4 company H, register of men discharged, #4 (James [sic] H Cathcart)
5 company H, descriptive roll, #28 (James H Cathcart)