John Canning Jr.
Occupation: Chairman, Madison Dearborn Partners
Canning works hardest these days at the Big Shoulders Fund, where he has helped raise more than $250 million for inner-city Catholic schools. But he is better known to many for his Big Pockets. The private equity firm he cofounded in 1992—Chicago’s largest—now has $13 billion under management and investments ranging from computer reseller CDW to baseball card and bubblegum maker Topps.