The overall pace of decarceration has varied considerably across states, but has been modest overall. Thirty-nine states and the federal government had downsized their prisons by 2017. Five states—Alaska, New Jersey, Vermont, Connecticut, and New York—reduced their prison populations by over 30% since reaching their peak levels. But among the 39 states that reduced levels of imprisonment, 14 states downsized their prisons by less than 5%. Eleven states, led by Arkansas, had their highest ever prison populations in 2017.
By yearend 2017, 1.4 million people were imprisoned in the United States, a decline of 7% since the prison population reached its peak level in 2009. This follows a nearly 700% growth in the prison population between 1972 and 2009.