The unit began life as the 321st Bombardment Wing in March 1953, operating B-47Bs and KC-97s at Pinecastle AFB, FL (later McCoy AFB) until inactivated in October 1961. The wing won SAC's Proud Shield bombing and navigation competition in 1957. The 321st was redesignated a Strategic Missile Wing, replacing the 4047th Strategic Wing in November 1964. It was reformed at Grand Forks AFB with the LGM-30F Minuteman II, upgrading to the LGM-30G Minuteman III in 1972. The unit was downgraded to Group status on 1 July 1994.