American football got its start when Rutgers played Princeton in the first intercollegiate football game in 1869. Earlier versions of the sport involved mobs of players trying to move the ball forward, but new rules improved and formalized play. Football spread, and other schools fielded teams. In 1879, the University of Michigan became the first school west of Pennsylvania to establish a college football team.

Football evolved in its early years. Refinements to the game included modifications to the size of the field, the institution of new scoring rules, and the introduction of a scrimmage line and a set of downs, among other changes. In 1906, the forward pass was legalized, revolutionizing the game.

High schools and local amateur athletic clubs also formed football teams to battle rivals on the field during the late 19th century. In 1892, the first paid player stepped onto the gridiron, and four years later, the first professional team was fielded. By the early 1920s, the National Football League had formed. The League's Cardinals team remains the oldest continuously run professional football operation in the United States.

Football fans are key to a successful team. Fans buy tickets and merchandise, cheer for their favorite players, and root their team to victory!

Football and Thanksgiving Day have been linked ever since the Intercollegiate Football Association scheduled its championship game on the holiday in 1876. Some long-standing rivals still compete on Thanksgiving, and National Football League games have become a viewing tradition. In 1934, the Detroit Lions played their first Thanksgiving Day game, and except for six years during World War II, they have played every year since.

The American Football League (AFL) was formed in 1959 and challenged the dominance of the National Football League. This new league was more successful than previous ones, which usually folded within a few years. The AFL's success led to an eventual merger of the two leagues in 1970.

League officials announced the NFL-AFL merger in 1966, but each league maintained separate schedules until the 1970 season. However, officials did agree to an annual AFL-NFL World Championship Game. On January 15, 1967, the NFL's Green Bay Packers defeated the AFL's Kansas City Chiefs. These end-of-season games were later dubbed Super Bowls.

The AFL lost the first two Super Bowls, leading many fans, sports writers, and experts to believe that American Football League teams were inferior to the National League's. That changed with Super Bowl III. The New York Jets, led by their talented star quarterback Joe Namath, upset the heavily favored Baltimore Colts.

The 1972 Miami Dolphins completed a perfect 17-0 season after winning Super Bowl VII -- the first and only NFL team to accomplish this feat.

Since 1869, football has become the most popular sport in America. The game is filled with names of famous players, coaches, and teams -- all cheered on by supportive fans. But more than the sport itself, football is known for the friendly pick-up games in the park on crisp autumn afternoons, families tossing a football in the backyard, and dreams of becoming a football star one day.