 Becoming active in politics as a Republican, he served as Assistant United States Attorney for New York's Southern District from 1861 until volunteering for the Union Army in 1862.Woodford took part in the American Civil War as chief of staff to Quincy A. Gillmore, commander of the Department of the South, and as commander of the 103rd Colored Infantry Regiment.He attained the rank of colonel and the brevet rank of brigadier general.