Enlisted on 17 August 1864 at Wilna, Jefferson County, New York at 20 years of age; mustered in on 5 September 1864, Company A, 186th New York Infantry Regiment as a Private; died of disease on 3 December 1864 in the Third Division Hospital at Alexandria, Virginia.

"Post-Mortem Records of the Continued Fevers. -- Cases in which the Diagnosis, Typhoid, is more or less sustained by the Clinical History. -- Case 79.— Private Abraham J. Cooper, Co. A, 186th N. Y.: age 20; admitted Nov. 30, 1864; typhoid fever. [The diagnosis at the Ninth Army Corps Field Hospital, on the 24th, was typho-malarial fever, and at the Depot Field Hospital, City Point, Va., on the 26th, remittent fever.] Symptoms on admission: Pulse varying from 90 to 110, feeble and thready; skin hot and dry; tongue dry, extremely red and gashed; teeth, gums and lips incrusted with sordes; deafness; stupor; low delirium. When undisturbed he lay with his eyes half closed muttering broken and unconnected sentences; when aroused he had a vacant expression and was unable to answer correctly. During the first twenty-four hours after admission he had four passages from the bowels; the abdomen was tympanitic, very tender over the small intestine and caeum, and marked with a few petechia and sudamina. Turpentine emulsion, laudanum and milk-punch were administered. Next day there was a slight improvement: the pulse became somewhat stronger, the tongue less tremulous and protruded with more ease; the patient was able to answer a few questions correctly, but the abdomina; symptoms continued and there was some epistaxis. On December 2 the pulse beeame somewhat stronger and less frequent, the tongue quiite moist, the sordes partially removed and the diarrhoea checked; but at 9 P. M. the diarrhoea returned, several involuntary stools were passed and the patient fell into a stupor from which he never aroused. He died at 3 A. M. of the 3d. -- Act. Ass't Surg. W. C. Minor, Third Division Hospital, Alexandria, Va." -- The Medical and Surgical History of the War of the Rebellion. Part III, Volume I. (3rd Medical volume) by U. S. Army Surgeon General's Office, 1888.