In 1974, lured by good wages, a 22-year-old African American college student from suburban Minneapolis started work as a pipefitter trainee for Minnegasco, a Minnesota natural-gas utility. Peggie Samples was one of the first four women hired by the company into non-secretarial jobs after the passage of the Equal Employment Opportunity Act of 1972. On the job, she and her beautiful blond friend Sonny met men who were hostile, men who were helpful, and men who were simply flummoxed to find "girls" in their midst. "S'long as a guy does his job," one told her, "it don't matter ta me if he's a...