BabeRuthGoudeycard3. 1930s Japan, public domain image.

A baseball card is a type of trading card relating to baseball, usually printed on cardboard, silk, or plastic. In the 1950s they came with a stick of gum and a limited number of cards. These cards feature one or more baseball players, teams, stadiums, or celebrities. Baseball cards are most often found in the U.S. mainland but are also common in Puerto Rico or countries such as Canada, Cuba and Japan, where top-level leagues are present with a substantial fan base to support them.