Originally laid down on 29 February 1944 as a Maritime Commission type (T2-SE-A2) tanker hull (MC hull 1819) under a Maritime Commission contract as SS "Mission Capistrano at the Marinship Corporation in Sausalito, California; launched on 7 May 1944; sponsored by Mrs. James E. George; and delivered on 14 June 1944. Chartered to Pacific Tankers Inc., she spent the rest of the War supporting allied forces overseas (during which time she was awarded the National Defense Service Medal), until returned to the Maritime Commission on 20 April 1946 and laid up at the Maritime Commission Reserve Fleet at Mobile, Alabama. Acquired by the Navy on 17 November 1947, she was designated as Mission Capistrano" (AO‑112) and transferred to the Naval Transportation Service for duty. She served with this service until 1 October 1949 when the Naval Transportation Service was absorbed into the new Military Sea Transportation Service (MSTS) and laid up at the Beaumont, Texas, Reserve Fleet.