In the early days, football was more blood than sport, a taste of the war a generation of young men had grown up without, an opportunity for valor and manhood where death was still a very real possibility. In fact, in 1905 alone, there were 149 injuries and 18 deaths nationwide, both at the high school and college level, prompting an ultimatum from President Theodore Roosevelt—there would be reform or football would be banned.
The titans of the sport at that time were not all that different than they are today. Though the names on their jerseys would draw a few strange looks nowadays - Harvard, Yale, the University of Chicago (etc.