Blacks don't have the “speed and rhythm” for factory work, declared the head of the Michigan Manufacturers' Association on the eve of World War II, and he assured government investigators that “most Michigan employers have the same belief.” This was certainly the belief and the practice among auto employers (with the eccentric exception of Henry Ford). They simply refused to hire blacks, except, occasionally, as janitors. Two years into the war, with black employment increasing in many automotive plants – as a combined result of the “labor shortage” and the UAW's push, in cooperation with the FEPC, to open jobs for blacks – auto employers were still complaining that blacks “leave the job easily and are absent a lot.” In “automobile equipment,” black employment was 3.6 percent in 1940 (overwhelmingly at Ford) and rose to a high of 15 percent in 1945.

“Employers in electrical manufacturing,” as Ruth Milkman points out, “were even more hesitant to hire blacks” than in the auto industry. In 1940, 0.5 percent of the workers in “electrical machinery” were black; a year after Pearl Harbor, the figure was only 1.3 percent; and at the wartime employment peak, it was only 2.9 percent.

Black employment was so low in electrical manufacturing because employers relied on reserves of white women workers to meet their requirements. Robert C. Weaver, head of the Negro Employment Office of the War Production Board, observed in 1946 that “those industries which delayed longest the employment of Negroes … were usually light and clean manufacturing.