The 1930s waxed paper wrapper for this chewing gum states "Start A Collection Of 500 Buttons." In addition to this set of presidents, sets were issued for baseball players, generals, Indians, movie stars as well as others. These are 13/16" lithos with paint that was very susceptible to attracting dirt and chipping. However, paint on this group is Exc.-Mint. The presidents (Washington through Hoover) are a basic set of 30. However, the set was also issued w/an error button and this group includes both the error "Howard H. Taft" as well as the corrected version "William H. Taft." Exceptionally clean paint on the entire set and the Taft error button is rarely seen as it was obviously withdrawn.