"Graf Zeppelin" Pan American Flight Cover, National Museum of American History

In the Post Office Department issued three postage stamps depicting the German airship LZ Graf Zeppelin The denominations of sixtyfive cents and paid the rates for postcards and envelopes send on various legs of the Graf Zeppelins Pan American flight from Germany to South America to North America and back to Germany The Zeppelin Company received a percentage of the postage to help defray its operating expenses The Washington DC post office postmarked this envelope on April the first day of issue of the three stamps The letter rate for the round trip from and to Friedrichshafen Germany was The sender of this example overpaid the rate by sixtyfive cents in order to create a souvenir with all three stamps