World League of American Football was created in 1991.
World Football League was created in 1974.
World League of American Football ended in 1992.
World Indoor Football League was created in 1988.
USA Network World League of American Football - 1991 was released on: USA: 23 March 1991
First of all, you are confusing the terms national league and American league used in baseball with football. Replace the word league with football. NFL has the National Football Conference and American Football Conference. There really is no difference, the difference is very similar to the differences between the American League and National League in baseball. Both Conferences are at the same level of play, play for the world championship with one team represting each (league in baseball, conference in football) in the final round of the playoffs, and in both baseball and football, each team plays the majority of games in their own (league in baseball, conference in football), but still plays a few of their games against teams from the other league or conference. These conferences were created after the NFL merged with a competing top-level league in 1970, the AFL (American Football League). All teams in the NFC are either expansion teams created after the merger, or were in the NFL before the merger. In the AFC, three teams that were in the NFL moved to the AFC the year of the merger so both conferences would have the same number of teams. Other than those three teams, all AFC teams were in the AFL or are expansion teams created after the merger.
World Football League ended in 1975.
World Indoor Football League ended in 1988.
In the world? The most popular sport is football. (Or call it soccer, if you are an American.)
The New York Yankees won the 1977 American League Pennant.
Matthew Reed was a professional football player, starring at quarterback in the World Football League and the Canadian Football League.
World Football Challenge was created in 2009.
Kiko World Football was created in 1998.