Basketball
Basketball was the answer to a clergyman's prayer. In 1891, Presbyterian minister James A. Naismith searched for a game that kids could play indoors year-round. In a moment of inspiration, he devised a game that called for fast players to throw a ball into a peach basket. His idea was a hit. By 1898, six teams formed the first professional National League. The modern National Basketball Association formed in 1949 and grew into a 22-team enterprise by the 1970s. The NBA raised its profile in the mid-'90s when professional athletes become eligible to play in the Olympics and overseas exhibition games.

The founding of American baseball, however, is a matter of dispute. Abner Doubleday claimed that he, not Cartwright, invented baseball in 1939 in Cooperstown, N.Y. After Doubleday died, a newspaper article linking the game's origins to rounders triggered a formal inquiry into baseball's origins. A seven-member commission concluded in 1907 that Doubleday was the sport's inventor. Additional evidence subsequently contradicted its findings. The controversy didn't stop Cooperstown from becoming the home of the National Baseball Hall of Fame in 1939.