as activated March 1943 at Ephrata Army Air Base, Washington, as one of the original squadrons of the 401st Bombardment Group.[1][2] The initial cadre for the squadron was drawn from the 395th Bombardment Group at Ephrata and the 383d Bombardment Group at Rapid City Army Air Field, South Dakota. The cadre soon departed for Orlando Army Air Base, Florida, where they conducted simulated combat missions with the Army Air Forces School of Applied Tactics out of Brooksville Army Air Field.[3]
The ground echelon moved to Geiger Field, Washington, in May 1943 and to Great Falls Army Air Base, Montana, in July. At Great Falls the first combat crews were assigned to the squadron.[4] In the final stage of training the squadrons dispersed with the 614th training at Glasgow Army Air Field.[5]
After completing training the ground echelon left for overseas on 19 October 1943. After staging at Camp Shanks, New York, they embarked on the RMS Queen Mary and sailed on 27 October disembarking at Greenock on the Firth of Clyde on 3 November 1943. The air echelon staged for deployment at Scott Field, Illinois, then flew to England under the control of Air Transport Command via Newfoundland, Iceland and Scotland.[5]