I posted earlier (right below this post) about where the term soccer came from, and in a display of typical arrogant American ethnocentrism it didn't even occur to me to try and figure out why we call American Football "football" when it is clearly not, at all, football.
American football seems to have evolved out of the same place as soccer (sorry for using the American name for it, but it would be confusing to have every game mentioned here as football). There were a wide variety of games in the mid-1800s that descended from "mob-football," a game played in England during the middle ages. These were all games in which an inflated ball was either kicked at a goal or carried over a line, and they were all called "football." By 1850s there were two main families of football being played in England: the kicking games and the carrying games. There were many games that involved elements of both. Rugby was actually the first carrying game with codified rules, as of 1845.
The first American Football team is claimed by some to be The Oneida Football Club which started in 1861…although no one knows the rules the played by. By the late 1860s the Canadians were playing Rugby, and that is said to have influenced the development of American and Canadian Football.
Rutgers University and Princeton University played a game in 1869 that shows some element of being the missing link between soccer, rugby and football. Here's how it went:
- Rutgers won, 6 goals to 4.
- It was played by two teams of 25.
- Two members of each team were stationed near their opponent's goal in the hope of scoring from unguarded positions.
- Each team was divided into 11 "fielders" and 12 "bulldogs".
- The ball could be advanced only by kicking or batting it with the
feet, hands, heads or sides. The rules banned throwing or running with
the ball. - Rutgers players formed "a perfect interference" around the ball.
- Rutgers players advanced the ball by "short, skillful kicks".
- A Princeton player threw himself into a group of Rutgers players, "bursting us apart, and bowling us over".
- One Rutgers player used a technique of kicking the rolling ball with his heel.
- An illustration on the Rutgers website suggests that they were using a round ball.
- Touchdowns were not a feature. (In fact none were recorded in games played by Rutgers until 1878-79.)
In 1876 a group of students met from Princeton, Yale, Rutgers and Harvard to standardize American rules for rugby. This was considered the birth of American football.
Between 1880 and 1883, Yale coach Walter Camp
devised a number of major changes to the American game—including some
major breaks with the rugby tradition—beginning with the reduction of
teams from 15 to 11 players; reduction of the field area by almost
half; and the introduction of the scrimmage, in which a player
heeled the ball backwards to begin a game. These were complemented by a
more significant innovation: a team had to surrender possession if they
did not gain five yards after three downs (successful tackles),
a rule introduced to thwart Princeton and Yale's strategy of
controlling the ball without trying to score. Camp also introduced the
seven-man offensive line, plus a quarterback, two halfbacks and a fullback in the backfield, an arrangement which soon became the norm.
It got dangerous though, a lot of players were dying and President Theodore Roosevelt threatened to outlaw the game if it wasn't made safer. To address this a series of meetings were held by 19 different universities. These meetings led to many restrictions on tackling and two more innovations: the first was the addition of a neutral zone
between the scrimmage lines, with a requirement that at least six
players from each team be positioned on them. The second was
legalisation of the forward pass, a major deviation from the game's forebear of rugby.
In 1912,
football fields were reduced in width by 35 yards, the value of a
touchdown increased to six points, and a fourth down was added, before
possession would switch. The game had gained the main attributes of its
modern form.
So to summarize the lengthy history lesson and get to the point, American football is called football because it evolved out of the group of games (including rugby and association football) collectively referred to as football.
(source: History of American Football, Wikipedia.org, some of it is direct cut and pasting and some is summarized, all is awesome)