[Air mail envelope commemorating 15th anniversary of air mail service]

Air mail envelope commemorating the 15th anniversary of air mail service, May 15, 1933. Addressed to the National Cachet Publishing Service in Brooklyn, New York.

Text from original exhibit label: "Airmail commemorating fifteen years of airmail service. Ironically the government would again fly the mail as they did in 1918, when regular airmail service began in this country, just eight months later."