The Incarceration Trends Project aims to inform the public dialogue, advance research, and help guide change by providing easily accessible information on jail and prison populations in every U.S. county. The centerpiece of the project is an interactive data tool, available at, that can be used for reference and measurement by justice system stakeholders and others looking to understand how their county uses jail and prison incarceration and how it compares to others over time. The tool allows users to explore particular problems within their jurisdiction—such as excessive growth or racial or ethnic disparities, among others.

The Incarceration Trends Project is supported by The Robert W. Wilson Charitable Trust and the MacArthur Foundation.

Project Objectives

  • To inform the public debate on mass incarceration and inspire data-driven reform.

  • To provide easily accessible information on how local level incarceration has changed since 1970.

  • To advance research on jails and prisons.

Key Fact & Resource