William M. Daley was born in Chicago on August 9, 1948. He is the son of the former Chicago Mayor Richard J. Daley (served 1955-1976) and brother of the former Chicago Mayor, Richard M. Daley (served 1989-2011). He graduated with a Political Science degree from Loyola University of Chicago and received a law degree from John Marshall Law School in 1975. From 1975 to 1985, he worked with the law firm of Daley and George. From 1985 to 1997, he was a partner with the law firm Mayer, Brown, and Platt, except for an interlude from 1990 to 1993 when he served several prominent positions with the Amalgamated Bank of Chicago.
Daley has been active in politics and public service at least since the 1980s. He advised his brother, Richard M. Daley on the latter's political career. In 1992, he helped Bill Clinton carry Illinois in the 1992 presidential election. In 1993, President Clinton appointed Daleyspecial counsel to the president on North American Free Trade Agreement (NAFTA), and in that position Daley helped convince enough senators to ratify that treaty. Daley worked for Clinton's successful reelection campaign in 1996, and in 1997, President Clinton appointed Daley U.S. Secretary of Commerce. As secretary, Daley eliminated a number of political positions to combat the Commerce Department's reputation for political favoritism. Daley also conducted several major trade missions; tried to involve the department in the field of E-commerce; and managed the 2000 Census. In 2000, Daley chaired the presidential campaign of Al Gore, who had served as vice president under Clinton. That campaign turned out to be one of the most contested elections in U.S. history, and Gore lost narrowly to George W. Bush. In 2019, Daley ran for Chicago mayor, but did not receive enough votes advance to the runoff stage of that election.