There have been many changes in the professional NFL leading up to what it is now. Modern professional football developed from rugby union between 1869 and 1876. In 1876 the first rules of American football were written. It was then that Walter Camp, who became known as the father of American football, first became involved with professional football. The first professional player in the NFL was made in 1982, William Heffelfinger. Then in 1898 an NFL professional touchdown was changed from four points to five points and was changed again in 1912 from five points to six points.
Earning their name in 1994 after changing their name 6 times between 1899 and 1994, the Arizona Cardinals, this professional football team remains the oldest continuous operation in football. In 1904 the field goal was changed from five points to four points and changed again in 1909 from four points to three points. The forward pass was not legalized in the NFL until 1906. In 1933, the American Professional Football Association changed its name to the National Football League.
There are two conferences in professional football, one is the American Football Conference and the second is the National Football Conference. These conferences were created in 1970 after the NFL merged with its competing top league, the AFL (American Football League). All NFC teams are either expansion teams created after the merger or were in the NFL prior to the merger.
Three professional football teams that were in the NFL moved to the AFC the year of the merger so that both conferences would have the same number of teams. Other than those three teams, all of the AFC teams were either in the AFL or are expansion teams created after the merger.
In the modern professional NFL, there are a total of 32 teams and they play 16 games in a single season.
