Her construction was awarded to Kaiser Shipbuilding Company, Vancouver, Washington under a Maritime Commission contract, on 18 June 1942, under the name Alikula Bay, as part of a tradition which named escort carriers after bays or sounds in Alaska.
She was laid down on 31 January 1944, and was assigned the designation MC hull 1132.
She was launched on 17 April 1944; sponsored by Mrs. Mabel C. Wallgren, wife of Senator Monrad Wallgren, under the name Alikula Bay.
She was renamed Bismarck Sea on 16 May 1944, as part of a new naval policy which named subsequent Casablanca-class carriers after naval or land engagements, and she was transferred to the United States Navy and commissioned on 20 May, with Captain John L. Pratt in command.

After being commissioned, Bismarck Sea engaged in training exercises off the West Coast throughout June.
On 1 July, she left San Pedro ferrying aircraft and pilots to Pearl Harbor.
After unloading her aircraft, she loaded more aircraft and ferried them to the Marshall Islands, arriving at Majuro Atoll on 16 July.
She then proceeded back to Pearl Harbor, carrying damaged aircraft, arriving on 29 July, along with her sister ship Saginaw Bay.
Throughout August, she was stationed at San Diego for a four-week overhaul, where she received her combat air contingent, Composite Squadron (VC) 86.
Between 7 September, and 16 October, she engaged in additional training exercises.
She then steamed to Ulithi, Caroline Islands, to join Admiral Thomas C. Kinkaid's 7th Fleet on 1 November.
Between 14 and 23 November, she operated off Leyte and Mindanao in support of operations onboard Leyte.
On 21 November, a Japanese aircraft made a strafing run along the carrier, but without inflicting any damage, and escaped to the northwest before it could be engaged.

On 27 November, she arrived at Seeadler Harbor, New Guinea, to join Task Group 77.4, commanded by Rear Admiral Calvin T. Durgin.
Throughout December, she conducted additional flight training and gunnery exercises.
On 27 December, she left for Palau, to support the invasion of Luzon.
On 5 January 1945, her task group sighted the Japanese destroyers Hinoki and Momi.
Bennion engaged in a brief and inconclusive firefight with the destroyers, before disengaging to provide a screen.

Twenty-four fighters and sixteen torpedo bombers were sent against the destroyers, which Bismarck Sea supplemented the strike group with four Avengers and the same amount of Wildcats.
The aerial strike force inflicted serious damage on both of the destroyers, sinking Momi.
Hinoki, albeit damaged, was able to escape into Manila harbor, but she was subsequently sunk on 7 January by aircraft from Task Force 78.
However, that same day, the escort carrier Ommaney Bay was sunk by a kamikaze aircraft.
The task group then participated in the Invasion of Lingayen Gulf and supported air operations over Luzon until 17 January, when the task group proceeded towards Ulithi in preparation for the invasion of Iwo Jima.
She departed Ulithi on 10 February, reorganized into Task Unit 52.2, still under the command of Durgin, and consisting of ten escort carriers and their destroyer screens, along with two escort carriers loosely tied into the task group on anti-submarine duties.
On 16 February, she arrived off Iwo Jima to support the landings.
The task group's aircraft conducted anti-submarine patrols, anti-aircraft patrols, and supported the first wave of troops on 19 February.
Close air support, almost all of it derived from carriers, played a major role throughout the invasion.
Her construction was awarded to Kaiser Shipbuilding Company, Vancouver, Washington under a Maritime Commission contract, on 18 June 1942, under the name Alikula Bay, as part of a tradition which named escort carriers after bays or sounds in Alaska. She was laid down on 31 January 1944, and was assigned the designation MC hull 1132. She was launched on 17 April 1944; sponsored by Mrs. Mabel C. Wallgren, wife of Senator Monrad Wallgren, under the name Alikula Bay. She was renamed Bismarck Sea on 16 May 1944, as part of a new naval policy which named subsequent Casablanca-class carriers after naval or land engagements, and she was transferred to the United States Navy and commissioned on 20 May, with Captain John L. Pratt in command.
After being commissioned, Bismarck Sea engaged in training exercises off the West Coast throughout June. On 1 July, she left San Pedro ferrying aircraft and pilots to Pearl Harbor. After unloading her aircraft, she loaded more aircraft and ferried them to the Marshall Islands, arriving at Majuro Atoll on 16 July. She then proceeded back to Pearl Harbor, carrying damaged aircraft, arriving on 29 July, along with her sister ship Saginaw Bay. Throughout August, she was stationed at San Diego for a four-week overhaul, where she received her combat air contingent, Composite Squadron (VC) 86. Between 7 September, and 16 October, she engaged in additional training exercises. She then steamed to Ulithi, Caroline Islands, to join Admiral Thomas C. Kinkaid's 7th Fleet on 1 November. Between 14 and 23 November, she operated off Leyte and Mindanao in support of operations onboard Leyte. On 21 November, a Japanese aircraft made a strafing run along the carrier, but without inflicting any damage, and escaped to the northwest before it could be engaged.
On 27 November, she arrived at Seeadler Harbor, New Guinea, to join Task Group 77.4, commanded by Rear Admiral Calvin T. Durgin. Throughout December, she conducted additional flight training and gunnery exercises. On 27 December, she left for Palau, to support the invasion of Luzon. On 5 January 1945, her task group sighted the Japanese destroyers Hinoki and Momi. Bennion engaged in a brief and inconclusive firefight with the destroyers, before disengaging to provide a screen.
Twenty-four fighters and sixteen torpedo bombers were sent against the destroyers, which Bismarck Sea supplemented the strike group with four Avengers and the same amount of Wildcats. The aerial strike force inflicted serious damage on both of the destroyers, sinking Momi. Hinoki, albeit damaged, was able to escape into Manila harbor, but she was subsequently sunk on 7 January by aircraft from Task Force 78. However, that same day, the escort carrier Ommaney Bay was sunk by a kamikaze aircraft. The task group then participated in the Invasion of Lingayen Gulf and supported air operations over Luzon until 17 January, when the task group proceeded towards Ulithi in preparation for the invasion of Iwo Jima. She departed Ulithi on 10 February, reorganized into Task Unit 52.2, still under the command of Durgin, and consisting of ten escort carriers and their destroyer screens, along with two escort carriers loosely tied into the task group on anti-submarine duties. On 16 February, she arrived off Iwo Jima to support the landings. The task group's aircraft conducted anti-submarine patrols, anti-aircraft patrols, and supported the first wave of troops on 19 February. Close air support, almost all of it derived from carriers, played a major role throughout the invasion.
USS Bismarck Sea