Born in Glasgow, Kentucky, Martin graduated Centre College, in 1844 was admitted to the bar in Mississippi, serving multiple terms as district attorney before the war. While himself opposing secession, he raised the Adams County cavalry troops, when war broke out, riding with them to Richmond, Virginia, the new Confederate capitol. Martin quickly rose to colonel of the Jeff Davis Legion, and served with J.E.B. Stuart's command through Autumn 1862. Promoted to brigadier general, Martin was ordered to the Western Theater, where he commanded divisions at Tullahoma and Chickmauga, and served as cavalry commander under James Longstreet at Knoxville. After Longstreet's return to the east, Martin was promoted to major general, led a division under Joseph Wheeler at Atlanta and rose to command of the military district of Northwest Mississippi by war's end.
After the war, Martin returned to his law practice in Mississippi, becoming trustee of both University of Mississippi and Jefferson College in Washington, Mississippi, served in the state senate, and was a delegate to Democratic National Conventions in 1868, 1872, 1876, and 1880. The president of the Natchez, Jackson, and Columbus railroad, he oversaw the construction of which in 1884. Martin died in Natchez, and is buried in City Cemetery,
- Boatner, Mark Mayo, III. The Civil War Dictionary. New York: McKay, 1959; revised 1988. ISBN 0-8129-1726-X.
- Warner, Ezra J., Generals in Blue: The Lives of the Union Commanders, Louisiana State University Press, 1964, ISBN 0-8071-0822-7.
- William T. Martin at Find a Grave Retrieved on 2009-04-21