Henry Martyn Whittlesey was born on August 12, 1821, in Hartford, Connecticut. He attended Yale University in the early 1840s and earned admission to the Connecticut bar in 1845. He moved to Detroit, Michigan, around 1854, and joined the local militia and volunteer fire department. He worked as a lawyer in Detroit, and by 1861, he was serving as the county’s Registrar of Deeds.
He received a commission as a captain in the Quartermaster’s Department on April 15, 1861. He received a series of brevet promotions: to major, lieutenant colonel, colonel, and finally to brigadier general. He remained in the army after the war, serving as chief Quartermaster of the Department of Mississippi in 1866. He also served as chief Quartermaster of the Freedmen’s Bureau. He mustered out on July 16, 1867, but he continued to work for the Freedmen’s Bureau until 1870. He was appointed comptroller of the District of Columbia later that year, and he died in Washington, D.C., on August 8, 1873.