Breton is a sound in Louisiana. Seattle-Tacoma launched her on 27 June 1942 under a Maritime Commission contract. Mrs. A. H. Rooks sponsored her. Captain E. C. Ewen commissioned her on 12 April 1943.
She spent the war with the Carrier Transport Squadron of the Pacific Fleet, carrying men, material, and aircraft to ships that were striking Japanese forces. On that duty she took part in the capture and occupation of Saipan, from 11 June to 10 August 1944, the Battle of the Philippine Sea on 19 and 20 June, the second Bonins raid on 24 June, and the assault and occupation of Okinawa on 6 and 7 April 1945.
She came back to the west coast in January 1946 after occupation duty in the Far East, prepared for inactivation at Tacoma, and went out of commission, in reserve, on 30 August 1946. She received four battle stars. On 12 June 1955 she was redesignated CVHE-23.