The NFL was founded in 1920 by George Halas and Bert Bell with two teams, now the Chicago Bears and Arizona Cardinals. It has since expanded to 32 teams split evenly between the NFC and AFC conferences. In the 2012-2013 season, the Baltimore Ravens beat the San Francisco 49ers in the Super Bowl, and in recent decades Super Bowl winners have included the New England Patriots, Pittsburgh Steelers, and New York Giants.