== History ==

The sport developed from informal games played in North America during the 19th century. Early games had a variety of local rules and were generally similar to modern [[rugby union]] and [[soccer]]. The earliest recorded instance of gridiron football occurred at University of Toronto's [[University College, Toronto|University College]] in November 1861.<ref name=Bernstein/>

Later in the 1860s, teams from universities were playing each other, leading to more standardized rules and the creation of [[college football]]. While several American schools adopted rules based on the soccer rules of the English [[Football Association]], [[Harvard University]] held to its traditional "carrying game". Meanwhile, [[McGill University]] in [[Montreal]] used rules based on [[rugby union]]. In 1874, Harvard and McGill organized two games using each other's rules. Harvard took a liking to McGill's rugby-style rules and adopted them.<ref name=Bernstein/><ref name="FootballInvented">{{cite web |last1=History Staff |title=Who Invented Football? |url=https://www.history.com/news/who-invented-football |website=[[The History Channel]] |publisher=[[A&E Television Networks, LLC]] |access-date=16 February 2023 |date=July 30, 2021}}</ref> In turn, they were used when Harvard and [[Yale University]] played their first [[intercollegiate sports]] game in 1875, and after which the rugby-style Canadian game was adopted by Yale players and spectators from Yale and [[Princeton University]].<ref name="FootballInvented"/> This version of the game was subsequently played with several other U.S. colleges over the next several years.<ref name=Bernstein/>

American football teams and organizations subsequently adopted new rules which distinguished the game from rugby.<ref name=PFRA2>{{cite book |chapter=Camp and His Followers: American Football 1876–1889 |title=The Journey to Camp: The Origins of American Football to 1889 |publisher=Professional Football Researchers Association |chapter-url=http://www.profootballresearchers.org/Articles/Camp_And_Followers.pdf |archive-url=https://web.archive.org/web/20100929152206/http://profootballresearchers.org/Articles/Camp_And_Followers.pdf |archive-date=September 29, 2010 |access-date=2010-01-26 |url-status=dead |df=mdy }}</ref> Many of these early innovations were the work of [[Walter Camp]], including the sport's [[line of scrimmage]] and the system of [[Down (American and Canadian football)|down]]s.<ref name="yalenews">{{cite news|url=http://news.yale.edu/2013/11/18/11-historic-tidbits-about-game|title=11 Historic Tidbits About The Game|last=Bishop|first=LuAnn|date=18 November 2013|newspaper=Yale News|archive-url=https://web.archive.org/web/20160303233722/http://news.yale.edu/2013/11/18/11-historic-tidbits-about-game|archive-date=2016-03-03|url-status=live|access-date=2017-01-24}}</ref> Another consequential change was the adoption of the [[forward pass]] in 1906, which allowed the [[quarterback]] to throw the ball forward over the line of scrimmage to a receiver.<ref>{{cite book | last = Vancil | first = Mark (''Ed.'') | title = ABC Sports College Football All-Time All-America Team | publisher=Hyperion Books | location = New York | year = 2000|page=18 | isbn = 978-0-7868-6710-3}}</ref> Canadian football remained akin to rugby for decades, though a progressive faction of players, chiefly based in the [[western provinces]], demanded changes to the game based on the innovations in American football. Over the years, the sport adopted more Americanized rules, though it retained some of its historical features, including a {{convert|110|yd|m|adj=on}} field, 12-player teams, and three downs instead of four.<ref name=Flaherty>{{cite book |last1= Flaherty|first1= David H. |last2= Manning|first2= Frank E.|date= 1993 |title=The Beaver Bites Back?: American Popular Culture in Canada |url= https://books.google.com/books?id=5xcRX1wwqy4C&q=%22Canadian+football%22+American&pg=PA16 |publisher= [[McGill–Queen's Press]]|page= 16|isbn=978-0-7735-1120-0 }}</ref> Around the same time Camp devised the rules for American football, the Canadian game would develop in the same way (but separately) from the American game; the [[Burnside rules]] were instrumental in establishing many of the rules for the modern game.<ref>{{cite web |url=http://greycup.cfl.ca/page/grey-cup-history-timeline-1900 |title=100th Grey Cup - Toronto - Grey Cup History Timeline 1900 |access-date=2015-01-18 |url-status=dead|archive-url=https://web.archive.org/web/20120922201718/http://greycup.cfl.ca/page/grey-cup-history-timeline-1900 |archive-date=2012-09-22 }} History of the Grey Cup</ref>