In the first decade of the 21st century the United States began to experience a shift in the 30-year buildup to a world record prison system. Although the decade ended with an increased number of people in prison, the rate of growth overall was considerably below that of previous decades and since 2008 the overall number of people in state prisons has declined slightly each year.

Scholars are beginning to analyze the relative contributions of changes in crime rates, criminal justice policies, economics, and demographics to the slowing growth rate of the prison system, but one area that has gone largely unexplored is the impact of such changes on racial disparities in imprisonment. As is well known, black/white disparities in the use of incarceration have been profound for quite some time. Since the 1980s a series of analyses have documented these trends at the national level as well as examining variation in disparity among the states.