If you mean American Football (NFL) it was founded in 1920, Canadian Football (CFL) it was founded in 1958 but you mean soccer i dont know
Indoor Professional Football League was created in 1998.
Hawaii Professional Football League was created in 2010.
Professional Spring Football League was created in 1991.
Eastern League of Professional Football was created in 1926.
Association of Professional Football Leagues was created in 1946.
American Professional Football League was created in 2003.
Portuguese League for Professional Football was created in 1978.
Bulgarian A Professional Football Group was created in 1924.
Women's Professional Football League was created in 1999.
Pacific Coast Professional Football League was created in 1940.
Junior Professional Football Club was created on 1980-03-19.
Bulgarian B Professional Football Group was created in 1950.