The relative size of the black population has been linked with the exercise of social control in both contemporary and historical contexts. In this article I use data from late nineteenth-century Georgia to examine several neglected issues: the multiple sources and targets of black threat, temporal changes in the relative size of the black population, and the rate at which black and white males were incarcerated. Time series analysis reveals that declines in the relative size of the black male and urban black population significantly affected the rate at which black males were incarcerated, particularly before disenfranchisement in 1909. In contrast, changes in the black population had no effect on the incarceration of whites. These findings suggest that declines in the relative size of certain segments of the black population threatened the labor supply and intensified social control efforts. I conclude by considering the empirical implications of these findings.