Togo issued a set of four stamps on May 1, 1960 to mark a Summit Conference between France Great Britain, the United States and the USSR which was to begin on May 16. On May 1 a US reconnaissance plane piloted by Francis Gary Powers intruded into Soviet airspace and was shot down. As a result President Khrushchev of the USSR left Paris and the Summit was not held. Powers was imprisoned by almost two years before he was exchanged for Rudolf Abel in 1962.
    The title in the upper, left corner of the stamps should not be "Congrès des Sommet," but rather "Congrès au Sommet," or "Confèrence au Sommet" according to Jean-Pierre Mangin.