https://www.prisonpolicy.org/data/

The Prison Policy Initiative Data Toolbox provides comprehensive national and state-level statistics on incarceration, community supervision and criminal legal system involvement. This includes data on jail and prison populations, probation and parole populations, pretrial detention, youth confinement and the demographics of people under correctional control. The initiative also maintains data sets examining mass incarceration trends, the economic impacts of the criminal legal system on families and communities, and disparities by race, gender and geography across the United States.

From Prison Policy Initiative