The first predecessor of the group was activated on 1 May 1943 as the 451st Bombardment Group at Davis–Monthan Field, Arizona, with the 724th, 725th, 726th and 727th Bombardment Squadron]]s assigned as its original elements. Although original plans were for the group to be an Operational Training Unit at Davis–Monthan, instead a cadre of the group moved to Dyersburg Army Air Base, Tennessee, where it was filled out by personnel drawn from the 346th Bombardment Group. Key group staff, plus the commanders and a model crew from each squadron received advanced tactical training with the Army Air Forces School of Applied Tactics at Orlando Army Air Base, Florida. This cadre joined the remainder of the group at Wendover Field, Utah for training with the Consolidated B-24 Liberator. The group continued its training at Fairmont Army Air Field, Nebraska, starting in September. On 18 November, the air echelon of the group departed Fairmont for staging at Lincoln Army Air Field, Nebraska to ferry their aircraft via the Southern Ferrying Route to the Mediterranean Theater of Operations. The ground echelon left on 26 November for the Port of Embarkation at Camp Patrick Henry, Virginia for transportation by ship.