Overview The American Football League stands as the only professional traditional outdoor football league to successfully compete against the NFL. When the two leagues merged in 1970, all ten AFL franchises and their statistics became part of the new NFL. Every other professional league that had competed against the NFL before the AFL–NFL merger had folded completely: the three previous leagues named "American Football League" and the All-America Football Conference (AAFC). From an earlier AFL (1936–1937), only the Cleveland Rams (now the Los Angeles Rams) joined the NFL and are currently operating, as are the Cleveland Browns and the San Francisco 49ers from the AAFC. A third AAFC team, the Baltimore Colts (not related to the 1953–1983 Baltimore Colts or to the current Indianapolis Colts franchise), played only one year in the NFL, disbanding at the end of the 1950 season. The league resulting from the merger was a 26-team juggernaut (since expanded to 32) with television rights covering all of the Big Three television networks (and since the 1990s, the newer Fox network) and teams in close proximity to almost all of the top 40 metropolitan areas, a fact that has precluded any other competing league from gaining traction since the merger; failed attempts to mimic the AFL's success included the World Football League (1974–75), United States Football League (1983–85), the United Football League (2009–2012) and the AAF (2019), and two iterations of the XFL (2001 and 2020), in addition to the NFL-backed and created World League of American Football (1991–92).
Overview The American Football League stands as the only professional traditional outdoor football league to successfully compete against the NFL When the two leagues merged in 1970 all ten AFL franchises and their statistics became part of the new NFL Every other professional league that had competed against the NFL before the AFL–NFL merger had folded completely the three previous leagues named "American Football League" and the All-America Football Conference (AAFC) From an earlier AFL (1936–1937) only the Cleveland Rams (now the Los Angeles Rams) joined the NFL and are currently operating as are the Cleveland Browns and the San Francisco 49ers from the AAFC A third AAFC team the Baltimore Colts (not related to the 1953–1983 Baltimore Colts or to the current Indianapolis Colts franchise) played only one year in the NFL disbanding at the end of the 1950 season The league resulting from the merger was a 26-team juggernaut (since expanded to 32) with television rights covering all of the Big Three television networks (and since the 1990s the newer Fox network) and teams in close proximity to almost all of the top 40 metropolitan areas a fact that has precluded any other competing league from gaining traction since the merger; failed attempts to mimic the AFL's success included the World Football League (1974–75) United States Football League (1983–85) the United Football League (2009–2012) and the AAF (2019) and two iterations of the XFL (2001 and 2020) in addition to the NFL-backed and created World League of American Football (1991–92)