The 20th century saw a major increase in popular and recreational mathematics. In North America and Western Europe there were a wide variety of products and publications designed to widen the appeal of the subject: games and puzzles to make math “fun,” and books and articles exploiting historical, psychological, philosophical, and literary aspects of the subject. This talk will concentrate especially on the United States in the 1950s and 1960s, when some notable popularizers were most active, including Martin Gardner, Clifton Fadiman, James Newman, and Constance Reid. I will conclude by raising questions about the success of past popularizations and prospects for the future.