Established as a Fourth Air Force bombardment squadron in November 1940 as part of the USAAC's buildup of forces after the outbreak of World War II in Europe; equipped with B-18 Bolos and early YB-17 Flying Fortress prototypes. Staging through the recently captured Tarawa and Makin Islands, the squadron attacked several atolls in the Marshalls, including Kwajalein. Between November 14, 1943 and April 1, 1944, the squadron carried out bombing missions over the Marshall Islands and participated in the actual invasion of Kwajalein in February 1944.