This large conglomerate, a creation of Chicago's Pritzker family, was the descendant of Pritzker & Pritzker, a law firm founded at the beginning of the twentieth century. By 1940, the firm had evolved into an investment company. In 1963, Jay and Robert Pritzker bought a large part of the Marmon-Herrington Co., a descendant of an automobile manufacturer. During the 1970s, the Pritzkers acquired the Cerro Corp., which had mining, trucking, and real-estate operations; their company was known for a time as the Cerro-Marmon Corp. The Marmon Group continued to grow during the 1980s, when annual revenues passed $3 billion. Among its holdings were the Trans Union Corp., a lessor of railroad cars; Braniff Airlines; and the Ticketmaster chain. By the early 2000s, Marmon owned about 150 companies—mostly in the service and manufacturing industries—had nearly $7 billion in assets, and employed 30,000 people worldwide, with over 2,500 in the Chicago area. In 2002, Robert Pritzker retired from Marmon after spending 48 years at the company's helm in its Chicago headquarters. Soon thereafter, efforts were launched to liquidate large portions of the immense assets of what was still Chicago's largest privately held company.

This entry is part of the Encyclopedia's Dictionary of Leading Chicago Businesses (1820-2000) that was prepared by Mark R. Wilson, with additional contributions from Stephen R. Porter and Janice L. Reiff.