Lewis Hine's 1920 Power house mechanic working on steam pump, one of his "work portraits", shows a working class American in an industrial setting. The carefully posed subject, a young man with wrench in hand, is hunched over, surrounded by the machinery that defines his job. But while constrained by the machinery, the man is straining against it—muscles taut, with a determined look—in an iconic representation of masculinity.Photo credit: Lewis Hine