During his 16-year career, he played for Columbus Crew and Seattle Sounders FC in Major League Soccer.

He finished the season with twenty-seven starts, and was a close second to Clint Dempsey in the voting for the MLS Rookie of the Year Award.

[6] He only played in twelve matches in 2007 due to ongoing concussion issues that threatened to end his career.

He led the defense on the squad that won both the Supporters' Shield and the MLS Cup 2008, a game in which Marshall scored the game-winning goal.

[8] On December 12, 2013, Marshall was traded to Seattle Sounders FC in exchange for allocation money and a third-round 2015 MLS SuperDraft pick.

Marshall was selected for the 2009 CONCACAF Gold Cup for the United States and received his first cap since 2005 in the side's opening match against Grenada.

On May 11, 2010, Bob Bradley, the U.S. Men's National Team head coach selected Marshall for the 30-man preliminary roster for the 2010 FIFA World Cup.

[21] On January 6, 2017, after almost seven years of absence from international soccer, Marshall was called for the United States national team by coach Bruce Arena.