Bates has 'John Allen' (1). The National Archives has no record of a John Allen in company D (2). The company D descriptive roll has a John Allert [?]; I assume Bates' transcriber misread that as Allen. See also the pension index, by regiment (5).
He was 40 years old when he was enlisted (3, 4). He was born in Germany (3).
He was 5 feet 8 inches tall, and had a dark complexion, grey eyes, and dark hair (3).
He also served in company B of the 10th Pennsylvania Infantry (5). He also served in company G of the 51st Pennsylvania Infantry (5). He also served in 120 company 2 battalion VRC (5). .
He was a substitute (1, 3, 4). He was enlisted and mustered into service on 23 or 24 March 1865 (1, 3, 4, 5). He was enlisted for one year, at Hollidaysburg, Pennsylvania, by Captain Eyster (3, 4). He was mustered in as a private, at Hollidaysburg, Pennsylvania (4). He reported for duty on 23 March 1865 (3). His service was credited to the seventeenth congressional district (3). He served as a private in company D (1).
He mustered out with his company on 10 July 1865 (1, 4, 5).
On 20 March 1886, he successfully applied for a pension (5, 6).
He died on 25 January 1895, at Osceola Mills, Pennsylvania (5).
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 Allen)
2 e-mail, Chris Buckingham, 5 March 2004
3 company D, [second] descriptive roll, entry 79 (John Allert [?])
4 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 6 August 2004 (John Allen)
5 pension index, by regiment, 91st PA Infantry, company D (John Allart)
6 pension index, by name (John Allart)
[I did not find an entry for him in the index on <www.ancestry.com> to the 1890 veterans' census (searched September 2006)]