He was born in 1816/17 (3 (44 in 1861)). He was born in Lancaster, Pennsylvania (3).
When he enlisted, he was 5 feet 6-1/2 inches tall, and had a dark complexion, dark eyes, and black hair (3).
He enlisted and was mustered into service on 6 November 1861 (1, 3). He was enlisted for three years, at Philadelphia, Pennsylvania, by C L Zinn (3). He was a private in company H (1, 7). He had rifle number 1 (3).
He was discharged at [illegible] Square Barracks, Washington DC on 13 April 1862 on surgeon's certificate of disability (1, 2, 3). He was a private, in company H (7).
A Casper Roberts was living at 344 Sergeant Street, Philadelphia, Pennsylvania, in February 1876 (6). On 16 February 1876, Magistrate Smith held him, setting bail at $600, on charges of "committing a cruel assault on his little daughter Sarah" (6). I do not know whether this is the Casper Roberts who served in the 91st (6).
He may be the Casper T Roberts, who was found dead under a barn in Garnet Street, below Somerset Street, Philadelphia, Pennsylvania, on 3 December 1884 (4, 5). That Casper Roberts died of pneumonia (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) (Casper T Roberts)
2 company H, register of men discharged, #16 (Casper T Roberts)
3 company H, descriptive roll, #60 (Casper T [?] Roberts)
4 [cause of death], Philadelphia Inquirer 6 December 1884, page 3 (I do not know whether this is the Casper Roberts who served in the 91st) (Casper Roberts)
5 [death notice], Philadelphia Inquirer 4 December 1884, page 3 (I do not know whether this is the Casper Roberts who served in the 91st) (Cooper T Roberts)
6 [assault], Philadelphia Inquirer 17 February 1876, page 2 (I do not know whether this is the Casper Roberts who served in the 91st) (Casper Roberts)
7 index to compiled service records of volunteer Union soldiers who served in organizations from the state of Pennsylvania (Casper F Roberts)
Pneumonia was found to have caused the death of Casper Roberts, whose body was discovered under a barn.
Cooper [sic] T. Roberts, formerly a well known builder, aged sixty years, was found dead yesterday under a barn in Garnet street, below Somerset.
Magistrate Smith has held in $600 bail Casper Roberts, residing No. 344 Sergeant street, to answer the charge of committing a cruel assault on his little daughter Sarah.