The group was first activated on 1 April 1943 at Davis–Monthan Field, Arizona as the 446th Bombardment Group with an initial cadre drawn from the 39th Bombardment Group.
Its original squadrons were the 704th, 705th, 706th, and 707th Bombardment Squadrons.
The cadre departed for Orlando Army Air Base, Florida for training with the Army Air Forces School of Applied Tactics, where they flew simulated combat missions from Montbrook Army Air Field.

The unit headed for Alamogordo Army Air Field, New Mexico in June 1943, but was diverted to Lowry Field, Colorado, where the group was filled out and advanced training was completed.
The group lost two aircraft to crashes during this training.
The ground echelon left Lowry on 18 October 1943 for Camp Shanks, New York and embarked on the RMS Queen Mary, sailing on 27 October 1943 and arrived in Greenock on the Firth of Clyde on 2 November 1943.
The aircraft left Lowry on 20 October 1943 for staging at Lincoln Army Air Field, Nebraska.
 The aircrews ferried their planes under the control of Air Transport Command via the southern route from Florida through Puerto Rico, Brazil, Senegal, and Morocco to England.
The 446th was the first Army Air Forces group to complete the Transatlantic hop from Brazil to Africa without the installation of additional bomb bay fuel tanks.
The group was first activated on 1 April 1943 at Davis–Monthan Field, Arizona as the 446th Bombardment Group with an initial cadre drawn from the 39th Bombardment Group. Its original squadrons were the 704th, 705th, 706th, and 707th Bombardment Squadrons. The cadre departed for Orlando Army Air Base, Florida for training with the Army Air Forces School of Applied Tactics, where they flew simulated combat missions from Montbrook Army Air Field.
The unit headed for Alamogordo Army Air Field, New Mexico in June 1943, but was diverted to Lowry Field, Colorado, where the group was filled out and advanced training was completed. The group lost two aircraft to crashes during this training. The ground echelon left Lowry on 18 October 1943 for Camp Shanks, New York and embarked on the RMS Queen Mary, sailing on 27 October 1943 and arrived in Greenock on the Firth of Clyde on 2 November 1943. The aircraft left Lowry on 20 October 1943 for staging at Lincoln Army Air Field, Nebraska.  The aircrews ferried their planes under the control of Air Transport Command via the southern route from Florida through Puerto Rico, Brazil, Senegal, and Morocco to England. The 446th was the first Army Air Forces group to complete the Transatlantic hop from Brazil to Africa without the installation of additional bomb bay fuel tanks.
446th Operations Group