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U.S. Prison Population Trends: Massive Buildup and Modest Decline

September 17, 2019
While most states have downsized their prison populations in recent years, the pace of decarceration is insufficient to undo nearly four decades of unrelenting growth.

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.

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.

If states and the federal government maintain this pace of decarceration, it will take 72 years—until 2091—to cut the U.S. prison population in half.

The United States has made only modest progress in ending mass incarceration despite a dramatic decline in crime rates. Reported crime rates have plummeted to half of their 1990s levels—as they have in many other countries that did not increase imprisonment levels. Expediting the end of mass incarceration will require accelerating the end of the Drug War and scaling back sentences for all crimes, including violent offenses for which half of people in prison are serving time.


Incarceration trends vary significantly among the states. By 2017, 39 states had at least modestly downsized their prison populations from their peak levels. Five states led the nation in reducing their prison populations by 30% or more:

• Alaska (39% decline since 2006)1)In 2019 Alaska’s state legislature repealed several aspects of a major criminal justice overhaul, Senate Bill 91.
• New Jersey (38% decline since 1999)
• Vermont (35% decline since 2009)
• Connecticut (33% decline since 2007)
• New York (32% decline since 1999)

Some Southern states, which have exceptionally high rates of incarceration, also achieved double-digit percentage reductions in their prison populations since reaching their peak levels. Specifically:

• Alabama (25% decline since 2012)2)Alabama’s prison population increased by 4% between September 2018 and June 2019 and recent changes in the state’s parole policies and practices are poised to further undo the state’s decarceration. See Alabama Department of Corrections. 2019. Monthly Statistical Report for June 2019. Available at:
• South Carolina (17% decline since 2009)
• Louisiana (16% decline since 2012)
• Mississippi (15% decline since 2008)

The federal prison population declined in size by 16% between its peak in 2011 and 2017—at over twice the nationwide rate of decarceration. The number of people held in federal prisons has since continued to decline.

These prison population reductions are the result of a mix of changes in policy and practice designed to reduce prison admissions and lengths of stay. While some critics have charged that decarceration would lead to rising crime, states with the most substantial reductions in their prison populations have often outpaced the nationwide crime drop. This pattern is most pronounced in New York State, driven by changes in New York City.  Between 1999 and 2017, the state downsized its prison population by 32% while the nationwide level of imprisonment increased by 10%. Meanwhile, New York’s declines in reported rates of murder, violence, and property crimes during this period far outpaced the nationwide crime drop.

Table 1. Change in New York and National  Reported Crime Rates, 1999-2017
Change in Violent Crime Rates Change in Murder Rates Change in Property Crime Rates
New York State  -39%  -44% -44%
United States -27% -7% -37%
Source: Federal Bureau of Investigations Uniform Crime Reporting Program

But overall, the pace of decarceration has been slow in most states. In 14 states the prison population reduction was less than 5%. Texas and Florida, which rank first and third highest among states in the size of their prison populations, have downsized their prisons by just 4% and 6%, respectively, since reaching their peak levels.3)California ranks second among states in the size of its prison population. While Texas has only modestly reduced its prison population, the state’s imprisonment rate—the number of prisoners per 100,000 residents—has declined by 27% between peak year 1999 and 2017, largely due to the state’s total population growing at over twice the nationwide rate during this period (38% versus 17%). Source: Bureau of Justice Statistics Prisoners Series and US Census. Eleven states had not achieved any prison population reductions by 2017, even though most are experiencing reported crime rates that are far below their peak levels. Among these states, the largest 5-year increases in prison populations since 2012 have occurred in Arkansas, with a 23% increase. Washington, Wyoming, Wisconsin, and Kentucky have also grown their prison populations by 10% or more during this five-year period.


Growing recognition of the scale and urgency of mass incarceration is now reflected in the work of leaders as diverse as Sen. Cory Booker and former House Speaker Newt Gingrich. A growing number of policy experts and advocacy organizations are now calling for a 50 percent reduction in the U.S. prison population within the next 15 years. These include the ACLU and JustLeadership USA.

But the sobering reality is that at the pace of decline since 2009, averaging 1% annually, it will take until 2091—72 years—to cut the U.S. prison population by 50%.

Table 1. Historical and projected U.S. federal and state prison population, based on 2009-2017 rate of decline
fig 1 for website
Sources of historical figures: Bureau of Justice Statistics (1982) “Prisoners 1925-81”; Bureau of Justice Statistics Corrections Statistical Analysis Tool; Bronson, J and Carson, E.A. (2019). Prisoners in 2017. Bureau of Justice Statistics. Available at

Clearly, waiting seven decades to substantively alter a system that is out of step with the world and is racially biased is unacceptable.

Expediting the end of mass incarceration will require intensifying sentencing reforms for non-violent crimes and making a meaningful dent into the number of people imprisoned for violence. Past reforms have helped to reduce the number of people imprisoned for a drug offense by 26% between peak year 2007 and 2016. The number of people imprisoned for a property offense has declined by 14% between peak year 2007 and 2016.

But for the half of the prison population imprisoned for a violent crime—which ranges from certain burglaries, robbery, and assault to rape and murder—reforms remain the exception. Overall, the number of people imprisoned for a violent offense has only declined by 2% between peak year 2009 and 2016. The reluctance to scale back excessive sentences for this population is at odds with evidence that long sentences incapacitate older people who pose little public safety threat, produce limited deterrent effect since they do not increase the likelihood of arrest, and detract from more effective investments in public safety.

Ending mass incarceration within our lifetime requires bold leadership to accelerate the pace and scope of reforms.

Figure 2: U.S. Prison Population by Conviction Offense, 1980-2016
fig 2 for website
Note: Reductions are calculated from year when the prison population for that offense category reached its peak. Based on sentenced prison population in state and federal systems. Chart omits public order and other/unspecified offenses, for which an additional 228,000 people were imprisoned in 2016, down 2% since 2014.
Source: Bureau of Justice Statistics Prisoners Series (1994-2017)
Figure 3. U.S. Prison Population Trends Through 2017: Decreases Since Peak Year, Increases Since 2012
big graph for website
Source: Bureau of Justice Statistics Prisoners Series (1999-2017)
Table 2: U.S. Prison Population Trends Through 2017: Decreases Since Peak Year, Increases Since 2012
Jurisdiction Peak to 2017 Peak Year
Alaska -38.9% 2006
New Jersey -37.8% 1999
Vermont -34.7% 2009
Connecticut -33.1% 2007
New York -32.3% 1999
Rhode Island -28.3% 2008
California -25.3% 2006
Alabama -24.5% 2012
Michigan -23.1% 2006
Hawaii -22.5% 2005
Massachusetts -19.7% 2011
South Carolina -16.8% 2009
Louisiana -16.1% 2012
Illinois -16.1% 2012
Federal -15.7% 2011
Maryland -15.6% 2007
Mississippi -14.9% 2008
Colorado -14.8% 2008
Maine -14.2% 2007
Indiana -13.1% 2013
Utah -9.0% 2013
U.S. total -7.3% 2009
Pennsylvania -6.5% 2011
New Hampshire -6.1% 2007
Oklahoma -6.1% 2016
Idaho -5.9% 2013
Florida -5.6% 2010
Georgia -4.4% 2009
Texas -4.3% 2010
Iowa -4.1% 2010
North Dakota -4.0% 2015
Virginia -3.2% 2015
Delaware -3.2% 2007
Montana -3.0% 2016
Nebraska -1.7% 2014
Arizona -1.7% 2015
Ohio -1.4% 2015
North Carolina -1.4% 2014
West Virginia -1.0% 2016
Minnesota -0.8% 2015
Oregon -0.2% 2015
Jurisdiction 2012 to 2017 Peak Year
Tennessee 2.0% 2017
Kansas 3.1% 2017
Missouri 4.3% 2017
Nevada 7.1% 2017
South Dakota 8.6% 2017
New Mexico 9.4% 2017
Kentucky 9.7% 2017
Wisconsin 10.8% 2017
Wyoming 12.2% 2017
Washington 13.2% 2017
Arkansas 23.4% 2017
Source: Bureau of Justice Statistics Prisoners Series (1999-2017).

Footnotes   [ + ]

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