Marine Eagle (MC hull 735) was laid down by the Sun Shipbuilding and Dry Dock Company of Chester, Pennsylvania under a United States Maritime Commission contract on 5 December 1942 and launched 10 May 1943 sponsored by Mrs. R. M. Stevenson. The ship was delivered to the War Shipping Administration on 18 September 1943 for operation by its agent the American-Hawaiian Steamship Company allocated to Army requirements. Marine Eagle, the only C4 completed as originally intended, as a tank carrier, operated between New York and European ports until July 1945. During those 18 months she completed nine eastbound Atlantic crossings to the United Kingdom and, after the Normandy invasion, French and Belgian ports. Departing Antwerp on 10 July 1945, she sailed to Panama, instead of New York, then headed out across the Pacific. For the next nine months she carried cargo to the Philippines, then, in March 1946, returned to the west coast. In May, she steamed to Portland, Oregon, for inactivation overhaul, after which she was laid up in the National Defense Reserve Fleet (NDRF) at Olympia, Washington, on 29 October.
The ship was reactivated on 27 March 1948 with title transferred to the Army Transportation Service which renamed the ship Private Leonard C. Brostrom, a Medal of Honor recipient for his actions in the Philippines in October 1944. After two years service, however, the ship was returned, on 3 March 1950, to the NDRF at Olympia. Private Leonard C. Brostrom was reactivated again, 9 August 1950, transferred to Navy custody and designated T–AK–255. Originally assigned to Military Sea Transport Service, Atlantic, she was converted for heavy lift in 1953–54 by the Bethlehem Steel Company of Brooklyn, New York. Transferred to the Pacific after conversion, the cargo ship sailed to the Far East to begin cargo operations under ComMSTSFE. Private Leonard C. Brostrom continued heavy lift operations through the 1960s and 1970s, carrying such diverse cargoes as chemical weapons to Okinawa for Project Red Hat in 1963 through 1964, a 101LT turbo-electric power plant, several 85LT diesel-electric locomotives (85 t. ea.), a 116LT turbine-generator car, and a 110LT IMODCO tanker mooring buoy from Yokohama to Taiwan.
Private Leonard C. Brostrom was removed from service in 1980 and entered into the NDRF at Suisun Bay, California on 29 May. She was sold for scrapping on 8 June 1982.