D.C. United is an American professional men's soccer club based in Washington, D.C. that competes in the Eastern Conference of Major League Soccer (MLS), the top tier of American soccer. Domestically, the club has won four MLS Cups, four Supporters' Shields, three U.S. Open Cups, and six Eastern Conference championships. In international competitions, the club has one CONCACAF Champions Cup title and one Copa Interamericana, the only United States team to win the latter. In terms of trophies won, it is the joint-most successful overall club in American soccer.