During the Korean War (1950–1953), the United States Congress made significant changes to the structure and role of the Army Reserves. These changes transformed the former Organized Reserve Corps into the United States Army Reserve, dividing it into a Ready Reserve, Standby Reserve, and Retired Reserve. Members of the Ready Reserve were authorized 24 inactive duty training sessions per year with their respective reserve unit. This translated into two duty days per month for twelve months and the commencement of regular "monthly drills" for reservists.