Image of 20c Parcel Post stamp of 1912<br>The 20-cent U.S. Parcel Post stamp of 1912 was the first stamp in history to depict an airplane, six years before the U.S. Post Office Department issued stamps for airmail service.
Bureau of Engraving and Printing; Composite photo and imaging by <a href="//commons.wikimedia.org/wiki/User:Gwillhickers" title="User:Gwillhickers"><i>Gwillhickers</i></a>
U.S. Post Office; Smithsonian National Postal Museum