This stamp was one of two issued in connection with the International Civil Aeronautics Conference, held December 12-14, 1928, in Washington, D.C. The conference commemorated the 25th anniversary of the first airplane flight, December 17, 1903, at Kitty Hawk, North Carolina, by Orville and Wilbur Wright. After spending 20 years in England, the Wright plane was returned to this country in 1948 and is now on view at the National Air and Space Museum of the Smithsonian Institution, Washington, D.C.