Rates of imprisonment have been declining among African-Americans for over a decade. This trend began long before the recent decline in the overall size of the prison population. The change is mainly due to reduced black male incarceration because prisoners are overwhelmingly male.
The decline in African-American women’s rate of incarceration remain important though, both in absolute terms and also in terms of the white-black disparity in imprisonment. This chart from the Bureau of Justice Statistics is striking. African-American women’s rate of imprisonment has plunged, while at the same time the white women’s rate has increased. The gap between the two hasn’t been this small in a generation.