Файл:Graf Zeppelin LZ-127 art detail in 1933, from- Zeppelin stamp, 50c, 1933 issue (cropped).jpg

Century of Progress U.S. Airmail stamp

In 1933 the German airship company Luftschiffbau Zeppelin G.m.b.H (Zeppelin Company) agreed to fly the LZ127 Graf Zeppelin to Chicago if the U.S. Post Office Department would issue a special postage stamp to help defray the enormous costs of the flight. On August 18 postal authorities agreed to issue a 50-cent zeppelin airmail stamp, 42½ cents of which would help offset the Zeppelin Company's expenses. The 50 cent stamp was designed by Victor S. McCloskey, Jr., which depicts the Graf Zeppelin air ship sailing over the Atlantic Ocean, to its destination of the Chicago World’s Fair.^[1]

Source