This dissertation is a study of settler colonialism in nineteenth-century Mexico and examines the racial politics of state formation, specifically from the ratification of the 1857 Federal Constitution to the establishment of the National Revolutionary Party (PNR) in 1929. It traces the development of a “customary law regime,” a form of state governance that gave legal recognition to Natives’ traditional forms of local rule. Unlike the Spanish colonial state (1521-1821), which created a society based on racial difference, the postcolonial Mexican state (1821-1917) attempted to build a post-racial nation founded on the concept of mestizaje (miscegenation), which would eliminate distinct racial groups through cultural and biological mixing. In Oaxaca, where two thirds of the population was Indigenous, statesmen incorporated Natives into the nation by giving legal recognition to their traditional forms of local rule, otherwise known as customary law. Far from being an emancipatory act, this recognition sought to eliminate Indigenous political subjects by making “Indian” claims obsolete. By the late nineteenth century, Native leaders no longer spoke of their rights as Indians: they now spoke of citizenship, democracy, and progress—the lexicon of the mestizo republic.