Below is a list of professional football Championship Games in the United States, involving: * the informal western Pennsylvania professional football circuit (WPC, 1890 to c.1910); * the 1902 "National" Football League and the World Series of Professional Football (WSF, 1902–1903); * the Ohio Independent Championship (OIC, 1903–1919); * the New York Pro Football League (NYPFL, 1916–1919); * the American Professional Football Association and the National Football League (NFL, 1920–present); * the All-America Football Conference (AAFC, 1946–1949); * the American Football League (AFL, 1960–1969); * the World Football League (WFL, 1974–1975); * the United States Football League (USFL, 1983–85); * the XFL (2001); * the United Football League (2009–2011); * and any inter-league chal