The nine corps areas, created by the War Plans Division under authority of United States War Department General Order No. 50 on 20 August 1920, had identical responsibilities for providing peacetime administrative and logistical support to the army's mobile units as was provided by the six territorial "Departments" they replaced. In addition, the corps areas took on the responsibilities for post and installation support units ("Zone of the Interior" units) created during World War I. Corps areas had the added responsibility for planning and implementing mobilization plans for all Regular Army, National Guard, and Organized Reserve mobile units in their respective geographic areas; the development and administration of hundreds of new Organized Reserve and Reserve Officers Training Corps (ROTC) units; and managing the personnel records for thousands of Reserve officers, enlisted personnel, ROTC cadets, and Citizens Military Training Camp (CMTC) candidates.