1909–11 American Caramel (E90-1)

Issued by the American Caramel Company of Philadelphia and packed one to a box of caramels, E90-1 is the best-known caramel set of the pre-war era. The backs promise "100 subjects," but collectors have since documented roughly 120 cards of 108 different players, printed across 1909–1911. Marketed to children rather than smokers, the cards took a beating, and PSA notes that only about 1% of graded examples top a 6. It holds the consensus rookie card of Joe Jackson alongside Cobb, Mathewson, Wagner, Young and Baker.