VMF-323 was commissioned August 1, 1943 at Marine Corps Air Station Cherry Point, North Carolina. According to oral history, the squadron got its name from three fighter pilots who killed a rattlesnake and hung its skin in the squadron's ready room. VMF-323 began training in F4U Corsairs almost immediately for combat in the Pacific theater of World War II. On December 16, 1943 the squadron received orders to prepare to move to the west coast of the United States beginning the first week of January 1944. Much of the new squadron's training was done at Marine Corps Air Station El Centro and Marine Corps Air Station Camp Pendleton, California. In July 1944, the "Death Rattlers" departed for the Pacific aboard . For the next nine months, VMF-323 flew training missions from secure island bases in the South Pacific.