Herbert Adolphus Miller (1875–1951) is a neglected figure within North American sociology, yet he made a distinctive contribution to the sociology and politics of race relations. He was one of the first sociological critics of eugenics and developed a distinctive approach to race relations and the position of subject minorities derived from a critical analysis of European empires. His approach was complementary to that of Du Bois with whom he had a close relationship. In this article, we trace Miller’s critique of eugenics and the idea of ‘Americanisation’ as a policy of immigrant assimilation, showing the distinctiveness of his approach within North American sociology, including the milieu of Chicago sociology with which he was associated. We also examine the connection between his sociology of race and Park’s position on race relations as being a process of gradual assimilation. We conclude with discussion of the Chicago school influence over Gunnar Myrdal’s The American Dilemma and the alternative approach to race relations that both Du Bois and Miller had already outlined in the 1920s.