An incisive conceptual history of global democracy in the transnational political thought of W.E.B. Du Bois. The Search for World Democracy traces the language of “world democracy” in W. E. B. Du Bois’s oeuvre, stretching from his early sociological writings to his later work on world peace and anticolonialism with and against the United Nations. Drawing on original archival research, several lesser-known writings, and most centrally Du Bois’s unpublished 1937 manuscript A World Search for Democracy, Adam Dahl places his unique approach to democratic theory within the transatlantic debates about the transformation of European imperial order in the twentieth century. Dahl shows how Du Bois’s vision of the spatial scale of democracy situated struggles for popular control, decolonization, industrial democracy, and racial enfranchisement in their shifting, multidimensional geographic contexts. Less a specific model of global governance than a radical politics of space and scale, Du Bois’s idea of world democracy challenges the boundaries between domestic and international politics by linking local sites of democratic struggle within and against the global color line. The Search for World Democracy shows how, for Du Bois, the radical transformation of the United States into a multiracial democracy would require an equally dramatic transformation of the imperial lineages of world politics.