Major League Soccer (MLS) is a professional soccer league based in the United States and sanctioned by the United States Soccer Federation (U.S. Soccer). The league is composed of 19 teams - 16 in the U.S. and 3 in Canada. MLS represents the top tier of both the American and Canadian soccer pyramids.
Major League Soccer was founded in 1993 as part of the United States' bid to host the 1994 FIFA World Cup. Unique for a major sports league, MLS operates under a single-entity structure, where each team is owned by the league and operated by its investors. The first season took place in 1996 beginning with 10 teams. Seasons presently run from March to November, with each team playing 34 games in the regular season. Ten teams compete in the postseason MLS Cup Playoffs culminating in the championship game, MLS Cup.
Major League Soccer's regular season runs from March to October with its 19 teams playing 34 games in an unbalanced schedule. Teams are divided into the Eastern and Western Conference. Midway through the season, teams break for the annual All-Star Game, a friendly game between the league's finest players and a major club from a different league. At the end of the regular season, the team with the highest point total is awarded the Supporters' Shield. The regular season is followed by the 10-team MLS Cup Playoffs ending with the MLS Cup championship final.
The 19 MLS clubs are divided among the Eastern and Western Conference. Each club is allowed up to 30 players on its first team roster. All 30 players are eligible for selection to each 18-player game-day squad during the regular season and playoffs.
Before its maiden season and inaugural draft, MLS allocated four marquee players across the initial ten teams. These inaugural allocations consisted of key U.S. national team and international players such as Eric Wynalda and Hugo Sánchez. By the 1998 season, the league added its first two expansion teams while the 2000 season saw the league reorganize from two conferences into three divisions: the Eastern, Western, and Central Division.
However, following the 2001 season, MLS contracted its two Florida franchises and returned to ten teams in two conferences. The league waited three more seasons before it continued its growth. Since the 2005 season, MLS has expanded by eight new clubs. This period of expansion saw Los Angeles become the first two-team market, the league's push into Canada, a renewed interest in original NASL-era names, and a growing national presence. Expansion continues in 2012 when the Montreal Impact join MLS as the 19th team. League executives are currently entertaining expansion offers for a 20th team in the near future.
As of the 2012 season, MLS has seen nineteen different clubs over the years with nine having won at least one MLS Cup, and eight winning at least one Supporters' Shield. Of the league's fifteen seasons, only six have seen the same club win both the Supporters' Shield and the MLS Cup.
