The story of football began sometime during the 19th century in England when a soccer player, frustrated at using only his feet to manipulate the ball, decided to simply pick it up and run with it. Although it was clearly against the rules of soccer, other players soon found the new way of playing soccer appealing and thus, the sport of rugby was born.
The new sport soon became a world-wide success that found its way into America by the mid-1800s. Played by many northeastern colleges, it was not long before Harvard University and Yale University met in Massachussetts in 1876 to formalize the rules to rugby that were similar to those in England. There were differences however: instead of playing with a round ball, the schools opted for an egg-shaped ball and the game's name was changed from rugby to football. To finalize the meeting, an organization called the Intercollegiate Football Association (IFA) was created to preside over the Americanized sport.
Football was still basically American rugby -- much different from the popular sport known today. Over the course of three years starting in 1880, Yale player Walter Camp eventually convinced the IFA to change a series of rules in football to create a game that is very similar to the one we know today. For his efforts, Camp is considered by historians as the father of modern football.
Nationalizing the Game
College football matured through the 1800's in a league of its own until the beginning of the twentieth century when professional football teams began appearing. By that time, college sports fell under the newly-established National College Atheletic Association(NCAA) so the rules of professional football were derived from the collegiate organization's guidelines.
When 1920 arrived, there were more than 10 professional teams across the United States. Organizers from the teams decided to meet in Canton, Ohio to form the American Professional Football Association(APFA) which later became the National Football League(NFL). The NFL continued to change the rules of the game and the game of football began to establish itself as an all-American past time.
Becoming a Popular Sport in America
From the time of the NFL's establishment, football's popularity caught on with the general public. The games played by the Chicago 
As football became a favorite sport with Americans, many leagues followed the NFL in trying to establish their own franchises. The NFL's dominance was so pervasive that many leagues did not even last beyond four years. Under millionaire Lamar
In another historic moment in football history, representatives from both the NFL and the AFL met in 1966 to agree on merging both leagues, but keeping the NFL name. Within the new league which actually began in 1970, two conferences were created that reflected the NFL's origins: the American Football Conference (AFC) and the National Football Conference(NFC). From then on, the two best teams from each NFL conference were set to play a championship game (later named the Super Bowl. This practice started with the two champions from the NFL and the AFL.
Football Today
One of the top sports in America, football has come a long way from the rebelling college students who wanted to play a different type of game. With the introduction of the television (which greatly increased football's accessibility to more parts of the United States) and the merger of the NFL and the AFL, football games became the most-watched television program. The ratings were as big as the profits. The titanic flood of fan interest generated billions of dollars by the 1990s. These enormous profits eventually trickled down to the players' salaries.
If change was how football began, it is change that has kept the sport's popularity high. The rules governing football have continued to evolve throughout the years to generate fan interest. For example, rules enacted in the 1970s promoted the passing game while placing less focus on the running game. Passing became less risky, and the rule change altered the complexion of the sport. In 1994, a greater emphasis was drawn from field goals to the two-point conversion. The game of football will continue to evolve with the times and provide Americans and people all across the world with a fun and enjoyable athletic experience.
from: http://www.football.com
