Walter Camp is widely regarded as the key figure connected with the creation and shaping of modern American football, earning him the title "Father of American Football." The sport evolved in the late 19th century from college games that blended rugby and association football, with Yale and other Ivy League schools playing pivotal roles in standardizing rules. Camp, a Yale alumnus, coach, and scholar, introduced foundational elements that defined the modern game: the line of scrimmage, the system of downs, the use of eleven players per side, the establishment of the quarterback position, and other rule changes intended to structure play and improve safety. His work during the 1870s–1880s helped separate American football from rugby and laid the groundwork for the sport as it is known today.