The 546th Bombardment Squadron (Heavy) was activated on 1 December 1942, at Gowen Field, Idaho, as a unit of the 384th Bombardment Group (Heavy). It was placed under the command of Captain George W Harris and commenced training at Wendover, Utah, on 2 January 1943, continuing there until 1 April 1943. The unit then moved to Sioux City, Iowa, for final training.
The Group received orders in late April to move to their combat assignment in England. Squadron aircrews left Sioux City with their new B-17Fs for Kearney, Nebraska on 3 May 1943, and then continued to Prestwick, Scotland via Presque Isle, Maine, and Goose Bay, Labrador; one contingent was routed via Gander, Newfoundland instead of Goose Bay. The ground unit left for Camp Kilmer, New Jersey on 9 May 1943, sailing on the Queen Elizabeth on 27 May 1943, and arrived in Greenock, Scotland on 2 June 1943.
On arrival in England, the 546th established its home at Grafton Underwood Airfield, Station 106, Northamptonshire. Combat training continued through June, and the Squadron flew its first operational mission on 22 June 1943, with six Squadron aircraft taking part. Combat losses were a fact of life from the very first mission, with one aircraft lost to enemy action from each of the 546th's sister squadrons, the 545th and the 547th. The first Squadron aircraft lost was on the the third mission with the Rosio Crew. Fortunately, all survived the bailout and explosion of the aircraft, with eight of them evading capture, and only two becoming POW.
Between 22 June 1943, and 25 April 1945, the 546th crews flew 2,494 sorties, against targets in Germany, France, Poland, Belgium, Czechoslovakia, and Holland. The Squadron lost 55 B-17s and 317 men, of whom 80 were KIA, 4 were MIA, 186 were POW, and 33 evaded: another 14 men were lost to other causes.
Captain (later Major) George W Harris ⇗ - 28 December 1942 to 29 May 1944
Captain (later Major) Gordon K Stallings ⇗ - 29 May 1944 to 30 September 1944
Major Arthur E Bean, Jr ⇗ - 30 September 1944 to 14 June 1945
Major Phillip Y Williams ⇗ - 15 June 1945 through the Istres period