Forbes magazine has reported the Pritzker family is worth $19 billion, although the vast holdings are now being divided among 11 cousins, the result of a family dispute, the newspaper said.
Pritzker's wealth started with The Marmon Group, a manufacturing firm in Ohio, that Pritzker over five decades built into a industrial conglomerate with annual revenues of $7 billion.
Robert Pritzker retired from Marmon in 2002, but then founded Colson Associates, a management services firm, where he served as president and chairman until his death on Thursday.
The firm manages Colson Group, a former division of Marmon that makes medical equipment through several companies.
The majority of Marmon was sold to Berkshire Hathaway in 2008 as part of the division of assets due to the family's rift.
Louhon Tucker, chief operating officer at Colson Associates described Pritzker as a man with "a very deep curiosity about manufacturing and about business."
"And after 50 years in business, whenever he was out at one of the plants -- and he got out frequently -- he would visit with people out on the shop floor. He was just as comfortable doing that as he was spending time with the president and the managing teams," Tucker said.
The Pritzker name is widely circulated in Chicago. It is attached to the Pritzker School of Medicine at the University of Chicago and the Pritzker Pavilion in Millennium Park.