He was born about 1829 in Philadelphia to Robert and Mary Lynn (2). No marriage record or pension application has been found (2). He was 23 years old when he was enrolled (7).
The Lynn family of Philadelphia were shipbuilders, and Jacob was awarded a contract to build a gunboat in 1861 (2).
They were members of the Kensington Methodist Episcopal Church where Colonel Gregory addressed the members on the day before the Battle of Gettysburg (2).
He was enrolled and mustered into service on 15 October 1861, at Philadelphia, Pennsylvania (1, 7). He served in company B (1).
He was promoted to corporal (4; 7).
He was killed in action on 3 May 1863 at Chancellorsville, Virginia (1, 3, 4, 5, 7). He was then a corporal (1, 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)
2 e-mail, 9 June 2001, Claire Labenz, citing New York Herald 11 July 1861 (re gunboat contract) and W Swindells, Annals of the Kensington Methodist Episcopal Church, 1801-1893 (published 1893) (re Kensington Methodist Episcopal Church)
3 consolidated morning report, 91st PA, 7 May 1863 (Corpl Lynn)
4 list of non-commissioned officers, co.B (Jacob A Lynn)
5 company B Register of deaths (Jacob A Lynn)
6 company B [first] descriptive roll, entry 8 (Jacob A Lynn) [no information]
7 Civil War Veterans' Card File, available at the Pennsylvania State Archives, searched 30 May 2004 (Jacob A Lynn; filed under 'Lynn, A')
[I did not find an entry for him in the index on <www.ancestry.com> to the pension index by name (searched March 2007)]