The 352d Fighter Group was activated at Bradley Field, CT, on 1 October 1942 and equipped with the Republic P-47 Thunderbolt fighter. The initial squadrons assigned were the 21st and 34th squadrons (under the command of 1st Lieutenant John C. Meyer) that dated back to 1917 and had participated in the defense of the Philippines, as well as the newly activated 328th. On 18 May 1943 the 21st and 34th were redesignated the 486th and 487th fighter squadrons.