The founders, John A Canning Jr, Paul J. Finnegan, Samuel M. Mencoff, and Nicholas W. Alexos, had previously made private equity investments for First Chicago Bank.

Madison Dearborn's chairman, John Canning, Jr., is also a minority owner of the Milwaukee Brewers baseball team and submitted an ultimately unsuccessful bid to buy the Chicago Cubs[5][6] In 1998, the firm bought Reiman Publications, based in Greendale, Wisconsin, from Roy Reiman for $640 million.

[18] Dan Primack at Fortune then published additional information about auxiliary benefits to MDP to buttress the break-even claim.

[19] In June 2007, Madison Dearborn, Providence Equity Partners and the Ontario Teachers' Pension Plan agreed to acquire Bell Canada Enterprises (BCE) in what would have been one of the largest leveraged buyouts in history.

The transaction was valued at C$51.7billion (US$48.5 billion) and was approved on September 21, 2007 by more than 97% shareholder votes cast by holders of common and preferred shares.