Before being appointed United States Secretary of Education in 2009, he served as Chief Executive Officer of the Chicago Public Schools system. As Secretary of Education, he spearheaded the Race to the Top school reform initiative.
After graduating from Harvard University with a degree in sociology, he headed the Ariel Education Initiative in Chicago and helped found the Ariel Community Academy charter school.
During the late 1980s and early 1990s, he was a professional basketball player in Australia.
His marriage to Tasmanian citizen Karen Luann Duncan resulted in a daughter and a son. The Duncans placed their children, Ryan and Claire, in public schools in Arlington, Virginia.
He served as Chicago CEO of Public Schools under the mayoral administration of Richard M. Daley.