Originally laid down as LST-840 by the American Bridge Company of Ambridge, Pennsylvania on 28 September 1944; launched on 15 November, sponsored by Mrs. C. W. Doerr; and commissioned on 11 December.
Following shakedown off Florida, LST-840 loaded cargo at Gulfport, Mississippi, then sailed on 14 January 1945 for the Pacific. Additional cargo stops were made at San Francisco and Seattle before departing for the Marshall Islands; she arrived at Eniwetok on 24 March. After preparations in the Marshall and Caroline Islands, the landing ship departed Ulithi on 12 April for Okinawa. The battle for this strategic island, which lay at the gateway to the Japanese homeland, was well underway when LST-840 arrived on the 18th. She unloaded combat engineers and equipment, then returned Ulithi on 5 May. 5 August the ship dropped off 500 tons of bombs at Iwo Jima and secured 25 Japanese pow's from the U.S. Marines and delivered them to Guam. For the remainder of World War II, she shuttled troops and cargo throughout the American staging areas in the Pacific. After V-J Day, LST-840 operated with U.S. occupation forces in Japan and Okinawa for the next three months. Embarking 500 marines at Guam, she departed on 11 November en route to Pearl Harbor and the United States. Arriving at San Diego on 15 December, she remained on the West Coast until she decommissioned at Vancouver, Washington on 1 June 1946, joining the Columbia River Group, Pacific Reserve Fleet.
In the effort to stop Communist aggression in South Korea, veteran ships were called out of reserve to provide support for the U.N. forces in Asia. LST-840 recommissioned on 3 November 1950. Following training off the West Coast and Hawaii, she loaded trucks and equipment, then departed Honolulu on 1 May 1951 for the Pacific staging areas. From June to November, the loading ship operated between Korea and Japan, shuttling cargo and prisoners of war along the war-torn peninsula. She returned to the United States on 27 November and, following overhaul, she departed Oakland, California on 16 May 1952 for duty in Alaska. LST-840 performed cargo operations there for six months before returning to San Diego. On 13 March 1953 she sailed on her second Korean tour, arriving at Yokosuka on 1 May. For the duration of the conflict, she remained in the Inchon vicinity and after the July truce continued peacekeeping operations in the Far East until late November.
After a stay in the United States, LST-840 was back in the Far East, arriving at Henrietta Pass, French Indochina on 28 October 1954. In the aftermath of the Indochina War, she loaded French troops and equipment and shuttled them along the coast of southeast Asia. Arriving Subic Bay on 22 November, she operated in the Far East until April, 1955 then steamed for San Diego.
LST-840 was named USS Iron County (LST-840) on 1 July 1955, and on 10 January 1956 she was en route to Pearl Harbor, her new home port. From January 1956 to November 1957 she performed amphibious exercises out of Hawaii, returning to the West Coast on 23 November.
Iron County remained at San Francisco until 1 July 1958, when she decommissioned, struck from the Naval Vessel Register, and transferred to the Republic of China under the Military Assistance Program.
She served the Chinese Nationalist Navy as ROCS Chung Fu (LST-223). Struck from the Republic of China Navy on 8 November 1997, her final fate is unknown.
LST-840 earned three battle stars for Korean War service.