An important American sociologist was W.E.B. DuBois who wrote about the "strange meaning of being black" and about the color line. In The Souls of Black Folk (1903) he announced his preoccupation with the "strange meaning of being black here in the dawning of the Twentieth Century." The strange meaning of being black in America includes a double consciousness that DuBois defined as "this sense of always looking at one's self through the eyes of others, of measuring one's soul by the tape of a world that looks on in amused contempt and pity." The double consciousness includes a sense of twoness: "an American, a Negro; two souls, two thoughts, two unreconciled strivings; two war- ring ideals in one dark body, whose dogged strength alone keeps it from being torn asunder."
In addition to writing about the "strange meaning of being black" and about racial mixing, DuBois also wrote about the color line, a barrier supported by customs and laws separating nonwhites from whites, especially with regard to their place in the division of labor. The color line originated with the colonial expansion that accompanied the Industrial Revolution. That expansion involved rival European powers (Britain, France, Germany, Belgium, Portugal, the Netherlands, and Italy) competing to secure colonies, and by extension, the labor and natural resources within those colonies. The colonies resources and labor fueled European and American industrialization.
DuBois traced the color line's origin to the scramble for Africa's resources, beginning with the slave trade upon which the British Empire and American republic were built, costing black Africa "no less than 100,000,000 souls".
DuBois maintained that the world was able "to endure this horrible tragedy by deliberately stopping its ears and changing the subject in conversation". He further maintained that an honest review of Africa's history could only bring us to conclude that Western governments and corporations' coveted Africa for its natural resources and for the cheap labor needed to extract them.