Theodore W. Allen's “Class Struggle and the Origin of Racial Slavery: The Invention of the White Race" (1975), a pamphlet that later was expanded into his seminal two-volume work "The Invention of the White Race", Vol. 1: "Racial Oppression and Social Control" (1994, 2012) and "The Invention of the White Race," Vol. 2: "The Origin of Racial Oppression in Anglo-America" (1997, 2012); has also been influential in this field. The argument was also in some regards anticipated by Abram Lincoln Harris' radical scholarship in the 1920s. Allen later wrote of Roediger's work: "...because of its almost universal acceptance for use in colleges and universities, has served as the single most effective instrument in the socially necessary consciousness-raising function of objectifying 'whiteness,' and in popularizing the 'race-as-a-social-construct' thesis. As one who has been the beneficiary of kind supportive comments from him for my own efforts in this field of historical investigation, I undertake this critical essay with no other purpose than furthering our common aim of the disestablishment of white identity, and the overthrow of white supremacism in general."