Major demographic and political changes in the late nineteenth and early twentieth centuries led to a reorganization of the American racial order. The federal census was a significant instrument of this reformulation of racial boundaries, racial hierarchy, and membership in the American polity. Three motivations conflicted and converged to produce a variety of classification schemes: politics, the drive for institutional or partisan control; science, the drive for scientific validity and professional legitimacy; and ideology, commitments to a particular formulation of the racial order. Through a discussion of the history of racial classification from 1850 through 1930, we show how racial categories, as well as their intersections and boundaries, were intensely debated and recreated. We consider the full array of groups with unstable boundaries, including what we now identify as blacks, whites, Native Americans, Asians, and Mexicans.

The analysis reveals how the nominal racial categories of recent decades were constructed, provides insights about our current era of newly unstable racial boundaries and hierarchies, and expands our analytic tools for studying intergovernmental relationships.