National Football League
In 1920, an American football league was formed. It was called the American Professional Football Association. In 1921 it changed its name to the National Football League. In 1960 another league was formed, called the American Football League. In 1970 the National Football League and the American Football League joined so that the teams from each league could play each other. The league called the National Football League changed its name to the National Football Conference (usually called the NFC) and the league called the American Football League changed its name to the American Football Conference (usually called the AFC). The two conferences together are now called the National Football League. People can also call it by the acronym NFL for short.