The United States Columbian Exposition set is a set of fifteen values that was issued in 1893 to commemorate the exposition of the 400th anniversary of Columbus’ discovery of the new world (the Exposition was a sort of early version of a World’s Fair). The stamps were the world’s first commemorative set and one of the first sets of stamps that was issued more to be saved by collectors than to be used for the carriage of mail, and collectors bought and put away large numbers of sets. Almost all still exist in collectors