Tanner was born “near” Clear Spring, Maryland, September 22nd, 1818. After receiving a degree from the University of New York in 1845, Tanner graduated from the College of Physicians and Surgeons in New York in 1847. He came to Shepherdstown where he practiced medicine until the onset of the War.
Tanner enlisted in Co. “F” 1st Virginia Cavalry as a 2nd Lieutenant April 18th, 1861. He served the 1st Virginia as Surgeon until November 1862 when he was appointed to the same position with the 21st North Carolina Infantry. Because of his skill, Tanner became Brigade Surgeon in 1863 and eventually became the Chief Surgeon of Maj. Gen. R. F. Hoke’s Division.
Following the War Tanner returned to Shepherdstown where he resumed his medical practice. Several of his descendents live in Shepherdstown.