Philadelphia Union has not yet won the US Open Cup, though the club has participated in the annual knockout tournament. The US Open Cup is the oldest ongoing national soccer competition in the United States, dating back to 1914.
The tournament features teams from all levels of the American soccer pyramid, from amateur clubs to MLS sides. It provides an opportunity for lower-division teams to face off against MLS clubs, occasionally producing memorable upsets. For MLS teams, the Open Cup represents a chance to win silverware outside of the league competition and earn a spot in the CONCACAF Champions League.