Aviation meet stamped envelope
The State Fair Aviation Meet took place in Milwaukee, Wisconsin, between September 13 and 17, 1915. Aviator Obert E. Williams flew a pouch of mail around the fair grounds each day. The mail was then taken to nearby West Allis Station and dispatched by regular means. Although Route No. 639,001 was authorized as a seven-mile trip to the Milwaukee Post Office, no attempt was made to fly outside the boundary of the fair grounds.
Williams carried this embossed envelope, addressed to W. C. Greene, Savannah, Georgia, on September 17. Postal officials canceled the 2-cent indicia with a black, circular postmark reading, "AEROPLANE STATION / SEP / 17 / 1915 / MILWAUKEE, WIS."