LST-521 was laid down on 4 October 1943 at Seneca, III., by the Chicago Bridge and Iron Co.; launched on 13 December 1943; sponsored by Mrs. Ruth Sexton; and commissioned on 9 February 1944, Lt. J. J. Kilthau in command.
During World War II, LST-521 was assigned to the European theater and participated in the invasion of Normandy in June 1944. Upon her return to the United States, she was decommissioned on 21 October 1945. On 1 July 1955, the tank landing ship was redesignated Cape May County (LST-521) after a county in New Jersey. The ship was struck from the Navy list on 1 November 1959.
LST-521 earned one battle star for World War II service.