W. E. B. Du Bois wrote in his 1935 book Black Reconstruction in America, 1860–1880 that normal labor unity did not work, due to “a carefully planned and slowly evolved method, which drove such a wedge between the white and black workers that there probably are not today in the world two groups of workers with practically identical interests who hate and fear each other so deeply and persistently and who are kept so far apart that neither sees anything of common interest.”
