This article develops a postcolonial and comparative reading of Tocqueville’s writings on slavery. It argues, first, that Tocqueville analyzed the ending of slavery as a revolutionary social transformation involving changes in laws, social relations and mores, and second, that he employed the same analytical framework consistently to discuss processes of abolition in the United States and in the French Caribbean Islands. In the United States the process of abolition of slavery was deepening rather than ending racist prejudices, racial segregation and hatred between the black and the white populations. This would, so Tocqueville predicted, undermine democracy in America. In the plantation colonies he believed the French could draw lessons from the English experiences when organizing the abolition process. Only when legal changes and changes in mores developed in tandem there could be economic and political stability in the aftermath of slavery. This would allow the French to end slavery peacefully, which he deemed necessary if they intended to continue exploiting the colonies. The article argues that Tocqueville demonstrated a deep and critical understanding of the reprehensible, long-lasting role of anti-black racism and slavery in barring the emergence of democratic cultures based on equal standing and integration across racial difference. Yet, he combined this critical perspective on racist slavery with an accepted defense of European supremacy and with a sense of pessimism about the possibilities for Africans to ever become capable of self-government.