The University of Michigan playing Michigan State University in American Football in Michigan, US in 1913. In the late 1800s and early 1900s, clubs and colleges started changing the rules of American Rugby which developed into American Football. The biggest change that made the game something completely different was the addition of the forward pass, which was added in 1906. As you can see, the goal post is at the touchdown line, some of the players are not wearing helmets, but the referee does still have a whistle. Football evolved drastically and is the most popular sport in the US. The rest of the world still does not really care for this sport, and with the deadly consequences of all the hits and concussions, the sport may have reached its peak.