Soccer is the fourth most popular sport in the United States behind American football, baseball, and basketball. The highest-level men’s professional soccer league in the U.S. is the Major League Soccer (MLS). It began in 1996 with 10 teams and has grown to 27 soccer teams with 24 in the United States and 3 in Canada. There are plans to further expand to 30 teams. Here are the best soccer clubs in the United States.