Lafayette was built at St. Louis, Missouri, in 1848 as Aleck Scott (often spelled Alick Scott). She was purchased by the War Department as Fort Henry on 18 May 1862 for use in the western flotilla. She was converted to an ironclad ram at St. Louis. Renamed Lafayette on 8 September 1862, she was transferred to the Navy with the entire western flotilla by executive order on 1 October 1862. She was commissioned at Cairo, Illinois, 27 February 1863, with Captain Henry A. Walke in command.