This historical monograph is one of a series of active duty and Reserve squadron histories. When completed, the series will cover each squadron in the Fleet Marine Force. This volume highlights the significant activities of Marine Fighter Attack Squadron 321 during its more than 40 years of active and Reserve service. Since its commissioning in February 1943, the squadron has evolved from a group of inexperienced wartime pilots flying F4U Corsairs to today's Reservists in their F/A-18 Hornets. During World War II, Marine Fighting Squadron (VMF) 321 enjoyed a brief, but successful, career as one of the many such units which contributed to the Allied victory in the Pacific. However, where many of its sister squadrons eventually disappeared during the postwar demobilization, VMF-321 was reborn at Naval Station Anacostia on the outskirts of the nation's capital as the first Marine Air Reserve fighter squadron, a role in which it continues to the present day.