The ship was originally authorized under the Lend-Lease Act as BAPM-5, the fifth of seven British Mechanized Artillery Transports, to be named HMS Portway (F144).

Sailing from Hampton Roads 19 July 1944, Casa Grande was delayed at Balboa, Panama Canal Zone for repairs en route to Pearl Harbor, where she arrived 21 August.

Between 12 September 1945, when she returned to Honolulu, and 20 April 1946, when she docked at San Francisco, Casa Grande supported occupation and redeployment operations in the western Pacific.

She ferried landing craft and motor torpedo boat squadrons, calling at ports in the South Pacific, China, Japan, Korea, Okinawa, the Philippines, and Alaska.

Exercises off the east coast, and supply missions to Newfoundland and Greenland, as well as amphibious training in the Caribbean, formed the pattern of her operations through 1960.

When Casa Grande sailed from Cephalonia a week later, she left behind a hospital corpsman, as well as details of Marines who began rebuilding homes and roads.

On her return to the States she cruised off the east coast in amphibious exercises and participated briefly in "Project Mercury" (man in space) operations.

Casa Grande sailed for 6th Fleet duty in November and finished 1962 in the Mediterranean as the command ship of Task Force 61 Amphibious Squadron Six.