The American artist Paul R. Meltsner (1905 - 1966) was one of many WPA artists given to depicting exhausted proletarians and his work can be found today in the vaults of every major American museum. Attached is a 1936 art review covering his one-man show at the Midtown Galleries in New York City:
"Meltsner builds his pictures everyday scenes of industrial life, dedicating them to labor and the machine...He gets broad vitality in his forms and force in his compositions, relieving at the same time the usual drabness of such scenes by a tonic of color."
Another 1936 article about Paul Meltsner can be read here.