Football didn’t really begin to take on any consistency of rules and boundaries until it was picked up as a sport in the seven major public schools of England in the early 1800’s. Six of the seven schools were largely playing the same game (including Eton, Harrow and Winchester) - while the seventh, Rugby School (founded in 1567) was playing a markedly different version of football.
The other schools moved ahead refining their rules and eventually their game became known as "association football" – or soccer, which was played back then much as it is today.
Rugby School went in a different direction. How and why the game developed differently at Rugby School appears to have been lost in history, but what is known is that by the 1830's, running with the ball at Rugby School was in common use and 18 foot goal posts had been added with a cross-bar at 10 feet above the ground.
The inclusion of the cross-bar was accompanied by a rule that a goal could only be scored by the ball passing over the bar from a place kick or drop kick. Apparently this was done to make scoring easier from further out and also to avoid the horde of defenders standing in and blocking the mouth of the goal.
Players who were able to "touch down" the ball behind the opponents goal line were awarded a "try-at-goal" - the player would make a mark on the goal line and then walk back onto the field of play to a point where a place kick at the goal was possible (a conversion). There was also an "off-your-side" rule used to keep the teams apart. Passing the ball forward was not allowed.
By the mid-1860s British schools and universities had taken up Rugby's game and honored the school by giving the "new football" the name of rugby.
The game soon went trans-Atlantic to America and landed on fertile soil.