22 May 1912. Lt. Col. Charles B. Winder of Ohio became the first Guardsman to be awarded a Reserve Military Aviator's rating. He earned it by completing the Army's aviation school at Augusta, Georgia.
23 May 1917. The First Aero Company, New York National Guard, was disbanded.
May 1918. Maj. Reuben Fleet, an Army officer and former Washington state Guardsman, organized the first U.S. air mail service. After World War I, he left the Army and founded the Consolidated Aircraft Corporation in Buffalo, New York.
22 May 1922. Members of the 136th Squadron, Tennessee National Guard, conducted a sham air battle for the public above the American Legion Field in Nashville.
7 May 1926. The 107th Observation Squadron, Michigan National Guard, received federal recognition.