The oldest defensive works still standing in the United States, constructed by the Spanish beginning in 1672 to protect St. Augustine, Fla.
Fort Marion (LSD-22) was launched 22 May 1945 by Gulf Shipbuilding Corp., Chickasaw, Ala.; sponsored by Mrs. Louise S. Dodson; and commissioned 29 January 1946, Commander H. A. Adams in command.
Fort Marion arrived at San Diego her home port, 26 May 1946, and through the next 3 years repaired landing craft, carried cargo and landing craft between San Diego and San Francisco, and took part in amphibious training exercises on the California coast. Between 4 April and 21 July 1949, she made her first tour of duty in the Far East, calling in Alaska outward bound.
Upon the outbreak of the Korean war, Fort Marion sailed for action 12 July 1950, and arrived at Pusan with Marines and their equipment 2 August. For the next month, she ferried troops from Kobe to Yokosuka for further routing onward to Korea. On 12 September, at Pusan, Fort Marion embarked men of the 1st Marines, whom she landed in the assault on Wolmi Do 3 days later. The seizure of this strategically placed island made possible the audacious landings at Inchon later that same day. Fort Marion lay off Inchon for the next month, receiving casualties and caring for small craft.
From 25 October 1950 until 23 November Fort Marion lay at Wonsan for similar duty, as well as aiding in the withdrawal early in December. From 29 December through March 1951, she carried troops from Japan to Korea, then embarked American and British Marines for a daring commando raid on the east coast of Korea. She put the commandos ashore 6 April, reembarking them that same afternoon after they had destroyed a section of a vital coastal railway. Fort Marion sailed from Yokosuka for home 26 April 1951.
During her second Korean war deployment, from 16 April 1951 to 14 January 1953, Fort Marion operated with a mine squadron in Wonsan Harbor, acting as mother ship for the small ships as they carried out their dangerous operations. She also operated with an amphibious construction battalion, and joined in a mock invasion on the coast north of Wonsan.
Extensively overhauled in 1953, Fort Marion was equipped with a mezzanine deck and fitted to carry helicopters. She arrived at Sasebo 7 December to resume duty as a minesweeper tender, and during this tour of duty joined in amphibious exercises off Okinawa and Japan. Back in San Diego 19 August 1954, she sailed later that year to the Hawaiian Islands for exercises, and in May 1955 took part in Operation "Wigwam", the experimental detonation of an underwater atomic explosion.
In 1956-57, 1958, and 1959, Fort Marion made additional deployments to the western Pacific, taking part in mine and amphibious warfare operations, and in the summer of 1958, joining in emergency operations to meet the threat posed by renewed Communist shelling of the Nationalist-held offshore islands. In September, serving with the Taiwan Patrol Force, she brought supplies to Quemoy under Communist fire. Fort Marion spent much of 1960 in an extensive modernization overhaul which added many useful years to her expected span of service, and on 22 November sailed for Far Eastern duty once more.
Fort Marion received five battle stars for Korean war service.