Huge men sprint across the field like gazelles, then smash into each other like trains. One man is alone inside a clear space while other men fight to protect him. Just before he falls under the weight of other bodies, he throws a ball high into the air. Thirty yards away, it is caught. A touchdown! The crowd goes wild.

This is American football. It's the most popular sport in the United States, but it's not well-known elsewhere. Two teams of eleven men fight to move along a 100-yard field. Each team defends its goal at the ends of the field. The men try to move a ball. The ball can be thrown, carried, or kicked. A team scores six points for carrying or throwing the ball across the other team's goal line, and three points for kicking the ball between the other team's goalposts.

American football (called "football" in the United States) evolved in the 19th century from different types of rugby, which is played in the United Kingdom. Rugby has a similar ball and similar rules to football. While American football is still clearly related to rugby, the two games are now very different.

American football was already a popular high school and college game before it was recognized as a professional sport in 1892. The first football league was established in 1920. Two years later, it changed its name to the NFL (National Football League), which still exists today.

After 1958, when a great championship game was played, football's popularity grew. Now, it is the most popular sport in the United States. The championship, now called the Super Bowl, is watched by more Americans than any other television event. The game, with its violence, strategy, and passion, is deeply rooted in American culture.

體型龐大的男性像瞪羚般地衝過運動場，然後像火車似的彼此相撞。一個人單獨在一片空地內，而其他男性爭相保護他。就在被其他人的身體壓垮之前，他將一顆球高高地拋入空中。它在三十碼之外被接住。達陣！而群眾為之瘋狂。

這就是美式足球，美國最受歡迎的運動，但它在其他地方並不是那樣為人所知。兩組各十一人的隊伍努力沿著一百碼的球場移動。二隊分別防禦著球場一端的球門。球員試著將球往前推進。他們可以丟球、帶球，或踢球。帶球或將球丟過另一隊的球門線可得到六分，將球踢入另一隊的球框中可贏得三分。

美式足球（在美國被稱為「足球」）是在19世紀，從不同種類的橄欖球演進而來的。橄欖球是英國發展出來的球類運動。橄欖球的球和規定都和足球類似。儘管美式足球顯然跟橄欖球系出同源，這兩種運動現在卻非常不同。

美式足球在1892年被認定為職業運動之前，就已經是在高中與大學裡十分受歡迎的運動了。第一個足球聯盟在1920年創立，兩年後，更名為現在仍存在的美式足球聯盟（簡稱NFL）。

1958年舉行了一場精采的冠軍賽，在那之後，足球的人氣就直線上升。它現在是美國最受歡迎的運動。冠軍賽（現在被稱為「超級盃」）在美國的收視觀眾比任何電視節目都要來得多。這個融合蠻勁、戰略及熱情的球賽已深植美國文化中。