Baseball card collecting is one of the most widespread American hobbies. For generations, children have assembled in living rooms and on front porches to trade cards with other neighborhood children. Adult collectors attend card conventions, place bids at sports memorabilia auctions, and even trade cards over the internet. Parents and children can build collections together. Baseball cards are clearly important to our mission to explore play; they symbolize our national pastime and have broad appeal with fans both young and old.