The 2004 MLS season was a landmark year that saw DC United capture their fourth MLS Cup championship, defeating the Kansas City Wizards 3-2 in the final at the Home Depot Center in Carson, California. The regular season featured 10 teams playing 30 games each, with the Columbus Crew winning the Supporters' Shield with 47 points.
The season was notable for the emergence of young talent, particularly 14-year-old Freddy Adu, who became the youngest player in MLS history when he signed with DC United and made his debut. Adu's signing generated significant media attention and helped raise the profile of MLS soccer. The season also featured strong performances from veterans like Jaime Moreno and Christian Gomez, who helped lead DC United's championship run.
The 2004 season continued MLS's growth trajectory, with improved attendance figures and increased television coverage. The league's salary cap remained modest, but the quality of play continued to improve as more international players joined MLS clubs and the league's development infrastructure expanded.