Seattle Sounders Football Club is an American professional soccer club based in Seattle. The Sounders compete as a member of the Western Conference of Major League Soccer (MLS). The club was established on November 13, 2007, and began play in 2009 as an MLS expansion team. The Sounders play their home league matches at Lumen Field, with a reduced capacity of 37,722 seats for most matches. Seattle has been among the league's most successful teams, winning the U.S. Open Cup four times, the Supporters' Shield in 2014, and the MLS Cup in 2016 and 2019. The Sounders are ranked as one of the most valuable franchises in North America.