John Canning Jr.
Occupation: Chairman, Madison Dearborn Partners
This hugely respected dealmaker is still a major power at the private equity firm he cofounded back in 1992—Chicago's biggest, with some $12 billion under management (2012 was a banner year: The firm delivered investors a record $3.3 billion.) Few things seem to happen in town without Canning's involvement. He's on the boards of everything from Exelon to Northwestern to the Museum of Science and Industry (see sidebar below), and he's one of the magnates behind the fledgling media company Wrapports, which owns the Sun-Times.
Photograph: E. JASON WAMBSGANS/CHICAGO TRIBUNE