William Scott Ketchum was born on July 7, 1813 in Norwalk, Connecticut. Graduated from the United States Military Academy, at West Point, New York in 1834. He served in the Seminole Wars and on the Western frontier. During the 1857 Cheyenne Expedition of Col. Edwin Vose Sumner against the Cheyenne and the Battle of Solomon's Fork, Captain Ketchum of G Company commanded the 6th Infantry Regiment detachment (of C, D and G Companies).