Three British Royal Air Force Squadrons (Nos. 71, 121 and 133) were transferred to the United States Army and redesignated as the 334, 335 and 336th Fighter Squadrons. These units had previously been established under British commanding officers with American pilots who, prior to the Pearl Harbor attack, were among the 9,000 Americans who had crossed the border into Canada to volunteer to join the Royal Canadian Air Force at the start of the war in Europe.
