National Postal Museum
Undercover: The Evolution of the American Envelope
May 6, 1997 – May 25, 2000
Patent models from 1849-1879, illustrations, and stories of the inventors examine the evolution of envelope manufacturing in the mid-1900s.
Smithsonian Institution
IK development site for ODI
National Postal Museum
May 6, 1997 – May 25, 2000
Patent models from 1849-1879, illustrations, and stories of the inventors examine the evolution of envelope manufacturing in the mid-1900s.
