Envelope Sent by Air Mail to Henry Ford from Plymouth, Michigan for National Air Mail Week, May 1938

Twenty years after the first regularly scheduled U.S. air mail service was established, President Franklin D. Roosevelt and Postmaster General James A. Farley sponsored National Air Mail Week in 1938. Part celebration and part advertising, the event promoted the pricier service during the Great Depression. Cities throughout the country created their own special mail cachets and cancellations to mark the occasion.