In 1920 representatives of several professional American football leagues and independent teams founded the American Professional Football Conference, soon renamed the National Football League. The first official championship game was held in 1933; prior to, there was no playoff system and instead the team that finished with the best regular season record was awarded the league title. By 1958, when that season's NFL championship game became known as "The Greatest Game Ever Played", the NFL was on its way to becoming one of the most popular sports leagues in the United States. In 1965, football supplanted baseball as the most popular televised sport in America. The merger with the American Football League, agreed to in 1966 and completed in 1970, greatly expanded the league and created the Super Bowl, which has become the most-watched annual sporting event in the United States.
