The Ohio Air National Guard was formed when the 357th Fighter Group, a highly decorated fighter unit in World War II, was inactivated on 20 August 1946, and its squadrons designated for assignment to the Ohio ANG. The official site of the Ohio Air National Guard notes that it is "descended from the 357th Fighter Group". The 357th Fighter Group was re-designated the 121st Fighter Group on 21 August 1946, and the 121st FG then allocated to the OHANG. In 1947, with the passage of the National Security Act of 1947 creating a separate Air Force, the Ohio Air National Guard came into being as a federally recognized reserve component. The 121st FG received its federal recognition on 26 June 1948.