Aviation units of the National Guard first began operating in 1915. The state of Ohio received its first aerial unit after World War I, when the 112th Observation Squadron (consolidated with the World War I 112th Aero Squadron on 20 October 1936) was constituted in 1921 and assigned to the 37th Division, but not activated. The 112th O.S. was organized and federally recognized on 20 June 1927, at Cleveland Airport. In 1933 the unit was assigned to the 45th Observation Group, a Regular Army Inactive (RAI) unit assigned to support the V Corps in wartime. The unit was inducted into federal service on 25 November 1940, and assigned to Pope Field, North Carolina, in support of the I Corps.