Part of the souvenir sheet honoring the Pan-American Exposition centenary, this is one of the famed inverted center examaples. This stamp shows an electric automobile, one of the various experiments that was being tested this early in the history of self-propelled vehicles. The other type of experimental vehicle that never took hold was powered by steam. The Pan-American Issue commemorated the Pan-American Exposition at Buffalo, NY. Purpose of the exposition was to promote friendly relations among all the countries of the New World. Designs of the stamps illustrate great engineering achievements of the time. All of the stamps were printed in two colors, unusual for the time.