In 1905, John K. Stewart and Thomas J. Clark—the same men who in 1897 had created the Chicago Flexible Shaft Co. (which became Sunbeam)—founded Stewart & Clark, which manufactured speedometers for automobiles. Between 1906 and 1908, annual sales rose from about $35,000 to $350,000. Although Clark died in a 1907 accident while demonstrating the product, the company continued to expand. By 1910, it had about 375 workers at its factory on Chicago's Diversey Avenue. In 1912, after buying the Warner Instrument Co. of Beloit, Wisconsin, another speedometer maker, the company became the Stewart-Warner Corp. In 1924, Stewart-Warner bought Bassick-Alemite, a maker of high-pressure auto lubrication equipment formed out of companies based in Chicago, Connecticut, and Cleveland. By the end of the 1920s, annual sales had reached about $40 million. Although business lagged during the Great Depression, Stewart-Warner employed about 2,500 people in the Chicago area in the mid-1930s, when the company made refrigerators and radios as well as auto parts. During World War II, the company manufactured bombs and shells, fuses, and engine parts, becoming one of the nation's top 100 military contractors in terms of volume of sales to the U.S. government (which came to about $330 million over the course of the war). The company did not grow much during the postwar years, but by the early 1970s, when annual sales stood at about $260 million, it still employed about 5,000 people in the Chicago area, many of them at plants on the city's West Side. In 1987, most of Stewart-Warner's operations were purchased by BTR, a British conglomerate. Over the next decade, the company's remaining divisions either downsized area operations or were acquired by larger companies. By the late 1990s, Stewart-Warner's Chicago presence had dwindled to the 20 employees at navigational equipment maker Stewart-Warner Electronics Corp. in Schiller Park.

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.