Major professional sports leagues in the United States and Canada
The Canadian Football League is the highest level of play in Canadian football. The league was organized in 1956 as a cooperative agreement between two regional leagues, the Big Four (which dated to 1907) and the WIFU (which was founded in 1936), and became independent from Football Canada in 1958. The league now consists of nine teams, all based in Canada. The Grey Cup is awarded annually to the champion every November and is the highest attended sporting event in the nation. The oldest extant teams, the Hamilton Tiger-Cats and the Toronto Argonauts, trace their origins to the late 1860s and early 1870s, which ranks them amongst the oldest professional sports teams of any kind still in existence on the continent. The CFL attempted an expansion into the United States in cities that had no NFL team between 1993 and 1995, though the expansion teams all either folded or relocated to Canadian cities.
Expansion of major sports leagues in the United States and Canada
The NFL is the only one of the major leagues to not have any teams based in any Canadian city; the closest teams to Canada are the Buffalo Bills, whose stadium is located south of the Canada–US border, and the Detroit Lions, whose stadium is located from Windsor, Ontario. Both border teams consider portions of Southern Ontario part of their markets, with the Lions drawing from Southwestern Ontario and the Bills from the Golden Horseshoe, which includes Toronto and Hamilton. In the 1950s and 1960s, selected NFL teams would travel north to Canada to play a CFL team in pre-season interleague games (as did the Bills, at the time in the American Football League). From 2008–13 the Bills played one regular-season game each year and sporadic pre-season games in Toronto. The Bills were drawing about 15,000 Canadian fans per game during the time the Toronto Series ran, and the Bills' then-owner, Ralph Wilson, saw Toronto's corporate market as key to securing the franchise's future; the Bills have effectively maxed out their revenue potential in the economically struggling Western New York region. (Wilson's successor, Terrence Pegula, canceled the Bills' Toronto games.) The league also has agreements with the CFL that date to the 1990s regarding the honoring of player contracts.