 Prior to the outbreak of the American Civil War, White was commissioned a captain of the Frontier Riflemen, which later became Company I of the 13th Virginia Volunteer Infantry Regiment, commanded by Colonel A. P. Hill in 1861.In 1864, he was commissioned as a colonel in command of the 23rd Virginia Volunteer Cavalry Regiment and served in that capacity until the unit disbanded in April 1865.Following the war, White returned to Romney and practiced law with John Jeremiah Jacob.