… is from pages 95-96 of Thomas Sowell’s 2013 volume, Intellectuals and Race (footnote deleted):
The last year in which black unemployment was lower than white unemployment – 1930 – was also the last year in which there was no federal minimum wage law. The Davis-Bacon Act of 1931 was openly advocated by some members of Congress on grounds that it would stop black construction workers from taking jobs from white construction workers by working for less than the union wages of white workers.