Lineage. Constituted as 561 Bombardment Squadron (Heavy) on 19 Dec 1942. Activated on 24 Dec 1942. Redesignated as 561 Bombardment Squadron, Heavy, on 20 Aug 1943. Inactivated on 28 Aug 1945. Redesignated as 561 Bombardment Squadron, Very Heavy, on 5 May 1947. Activated in the Reserve on 12 Jun