Major League Soccer
MLS, founded in the United States, is a fully professional league with 28 teams, three of which are based in Canada. The United States Soccer Federation (USSF or U.S. Soccer), which runs soccer in that country, considers MLS to be the country's top men's league. The Canadian Soccer Association (CSA), which runs soccer in Canada, considers the Canadian Premier League as its top men's league, but MLS has much greater Canadian media coverage and is seen as having a higher level of play. Referees are approved by U.S. Soccer and the CSA. In turn, both national governing bodies are members of FIFA, which governs all play between national teams and sets the rules for the sport along with the national governing bodies of England, Northern Ireland, Scotland, and Wales.