A recent addition, a LET'S GO! CITIZENS MILITARY TRAINING CAMPS slogan from Baltimore, 1926.
Payne shows 11 cities (not counting numerous stations) using this International version from 1924 to 1929.
The delightful aspect of this cover is the return address and printed promotion from Third Corps Army which invites the viewer to participate in the program. The envelope likely mailed a news release about the program as it is addressed to a Pennsylvania newspaper, The Item.