She was laid down on 13 May 1942 at San Francisco, California, by the Western Pipe and Steel Company under a Maritime Commission contract (MC hull 269); launched as SS Sea Angel on 7 September 1942; sponsored by Mrs. Robert W. Ethen; originally designated a transport, AP-79; reclassified APA-34 on 1 February 1943; transferred to the Navy on 15 March 1943; commissioned that same day, as Bolivar, moved to Hoboken, New Jersey; decommissioned there on 23 April; converted to an attack transport by Todd Shipbuilding Company; and recommissioned on 1 September.

On 30 May, Bolivar steamed out of Pearl Harbor with units of the 16th Marines embarked as part of Transport Group "Able" bound for Saipan in the Mariana Islands.

On the 18th, she and the other auxiliaries received orders to head for a safe area east of Saipan where they remained until the Battle of the Philippine Sea was won on 20 June.

At Pearl Harbor, Bolivar embarked a unit of the 306th Regimental Combat Team (RCT) of the Army's 77th Infantry Division and got underway for Guam on 9 July.

After embarking a battalion of the Army's 383d Regiment, Bolivar rehearsed landing maneuvers at Maui, ostensibly for the invasion of Yap Island.

The attack transport left Pearl Harbor on 15 September but, one day out of port, received orders cancelling the Yap campaign and directing Bolivar to Manus in the Admiralty Islands.

On 14 October, Bolivar stood out of Seeadler Harbor as part of Transport Group "Baker" of the Southern Attack Force headed for Leyte.

Bolivar completed her unloading the next day and, with her squadron, threaded her way through the aircraft defense smoke cover and headed south for Hollandia, New Guinea, carrying casualties to the Army hospital there.

The transports arrived at their designated anchorages in lower Lingayen Gulf by 0700 on 9 January 1945, despite heavy enemy air attacks which crashed the aircraft carrier Kitkun Bay and narrowly missed the Australian ship HMAS Westralia in column to port of Bolivar.

After unloading cargo and troops in a scant eight hours, the transport took on board badly wounded crewmen from the battleship California which had been hit by a kamikaze on 6 January.

Cargo holds empty, the first echelon of transports, including Bolivar, left Lingayen Gulf at dusk through the smoke screen and the continuing air attacks.

After transferring the casualties and other passengers and unloading ammunition, Bolivar made the short overnight run to Portland, Oregon, where she began a general overhaul at Kaiser Shipbuilding Corporation's Swan Island yard on the 18th.

The war ended before the attack transport completed overhaul but, on 2 September, she put to sea as part of the Operation Magic Carpet fleet returning veterans from the Philippines, Marshall, Admiralty, and Caroline Islands.