What Percent of the U.S. Is Incarcerated?

Why does the U.S. rank highest for incarcerated people? Learn how historical policy shifts led to mass incarcerations and affected generations.

two men in prison cell

Initially, the United States aimed to create a justice system that protected the convicted or accused’s rights, with four of the initial 10 amendments focused on this cause. However, punitive policies and federal funds fueled mass incarceration disparity affecting poor and minority households while filling pockets of private industries.

Since the 1970s, the incarceration rate has steeply increased, leading to 0.7% of the U.S. population or 698 out of 100,000 people being behind bars.1 A rate that ranks the U.S. and nearly all individual states higher in incarceration than all other countries.

In this article, we’ll examine how and why the U.S. came to have the highest incarceration rate globally, including the intersection with race and poverty, while exploring incarceration’s diminishing return and future approaches.

Four Decades of Increasing Prison Populations

In the early 1970s, the incarceration rate was an estimated 150 to 160 people per 100,000.2 By the mid-1970s, political rhetoric and popular phrases—like being “tough on crime” or fighting a “war on drugs"—backed by punitive policies fueled prison population growth.

Between the mid-1970s and the mid-1980s, the incarceration rate doubled to roughly 300 people per 100,000. During President Reagan’s term alone, between 1981 and 1989, the prison population nearly doubled to 627,000 incarcerated people.2 This swift upward trend was supported by laws such as the Violent Crime Control and Law Enforcement Act of 1994, as well as policies aimed at lengthening sentences for drug and violent crimes, with terms such as “three strikes” or “truth-in-sentencing.” It led to steep increases until hitting a record high of nearly 2.3 million people incarcerated in 2007.3

A Decline After 40 Years of Growth

The growth plateaued and slightly decreased by 2012, with 707 people per 100,000 incarcerated.4 The numbers continued to shift marginally lower, with the U.S. Department of Justice reporting, “The adult incarceration rate has declined every year since 2008, and the rate in 2018 was the lowest since 1996.”5

In 2018, the prison population was 2,123,100 people, and it dropped to 2,115,000 by 2019.5,6 After months of a global pandemic, the late 2020 population had fallen to 1,814,800 people.6

Why Incarceration Rates Rose

According to the National Research Council, the two leading causes are “the result of increases both in the likelihood of imprisonment and in lengths of prison sentences.” The council notes, “the increase in the use of imprisonment as a response to crime reflects a clear policy choice.”7 However, the 2014 report mentions other factors, such as:

  • Rising crime rates during the 1970s and 1980s
  • Police focusing on “street-level arrests of drug dealers”
  • Attitude changes in justice officials resulting in harsher sentences

But these are part of the overall guidelines that encouraged—and even rewarded prisons for— higher incarceration rates and longer sentences.

Drug Arrests

The drug arrest rate more than doubled between 1980 and 1989, partially due to Reagan’s Anti-Drug Abuse Act in 1986, which increased the incarceration of nonviolent offenders. By 2010, incarcerations for drug crimes doubled again.4 Although there’s been a decline, according to the Prison Policy Initiative, “in 2019, 46% of people locked up in federal prisons were serving time for a drug offense, while only 8% were serving time for a violent offense.”8

Longer Sentences for Some Crimes

Prior to the mid-1970s, national sentencing laws were scarce. The federal government provided guidelines but left it up to individual officials, states, cities and counties to decide how to sentence people. Indeterminate sentencing fell out of favor as crime rose, leading to the enactment of determinant policies throughout the 1970s and 1980s. Policies supported imposing stricter and longer minimum sentences and created minimum bail money amounts.

Prison Privatization

Before 1980, private prisons weren’t common. By 2013, Bloomberg reported that “the number of inmates in for-profit prisons throughout the U.S. rose 44%.”9 Corporate prison operators lobby federal and state governments to expand policies increasing incarceration. Moreover, lucrative private contracts feature lockup quotas, giving the private company a guaranteed income if the state fails to keep prison beds filled.

The Racial Impact of Incarceration

Time and again, laws were passed under the guise of reducing racial disparities and unfairness. And over and over, each one failed. Policing targeting impoverished areas led to increases in minority arrests. The 100:1 disparity in crack cocaine versus powder cocaine affected minority, women and youth populations far more than other counterparts.

By 2000, “one in 10 Black males between the ages of 20 and 40 was incarcerated — 10 times the rate of their white peers.”10 Today, Black Americans represent 13% of U.S. residents yet make up “40% of the incarcerated population.”11

U.S. Incarceration Rates Versus the Rest of the World

According to Statista, “as of June 2020, the United States had the highest prison rate, with 655 prisoners per 100,000 of the national population.”12 The other countries in the top five include El Salvador, Turkmenistan, Thailand and Palau.

Nearly all U.S. states have higher prison populations than other countries. In 2018, Oklahoma led the prison leaderboard with 1,079 per 100,000 people.13 El Salvador is closest to this figure, with 614 people out of 100,000 incarcerated. Although other countries may have similar numbers of prisoners entering the system, the lengthy prison sentences in America are one reason for higher overall rates.

The Diminishing Returns of Incarceration

Up to a certain point, removing violent offenders from the streets can reduce crime. However, increasing incarcerations doesn’t equal a similar decline in crime. A Sentencing Project report finds, between 1984 to 1991, states with increased incarcerations saw an average of 2% “less of a rise in crime than other states.” Between 1991 to 1998, “states with the largest increases in incarceration experienced, on average, smaller declines in crime than other states.”14

Furthermore, states with higher incarceration levels paid dearly for it, with the Sentencing Project reporting the estimated cost for the 2% gain was $9.5 billion.14

Moving Forward: What Comes Next?

Although prison populations dropped in 2020, the number began to rise again near the end of the year, with county jails seeing steeper increases than state or federal-run facilities.6 The current situation stems from decades of policy changes, and changing mass incarceration will take significant shifts at the national, state and local levels.

If you’d like to be part of the future of prison reform by bringing new solutions and actions to the table, consider how an M.A. in Criminology and Criminal Justice from Kent State University can help you.


  1. Retrieved on April 1, 2021, from prisonpolicy.org/blog/2020/01/16/percent-incarcerated/
  2. Retrieved on April 1, 2021, from brennancenter.org/our-work/analysis-opinion/history-mass-incarceration
  3. Retrieved on April 1, 2021, from abcnews.go.com/TheLaw/story?id=5009270&page=1
  4. Retrieved on April 1, 2021, from nap.edu/read/18613/chapter/4
  5. Retrieved on April 1, 2021, from bjs.gov/content/pub/pdf/cpus1718.pdf
  6. Retrieved on April 1, 2021, from vera.org/downloads/publications/people-in-jail-and-prison-in-2020.pdf
  7. Retrieved on April 1, 2021, from nap.edu/read/18613/chapter/5
  8. Retrieved on April 1, 2021, from prisonpolicy.org/blog/2020/10/30/prisoners_in_2019/
  9. Retrieved on April 1, 2021, from bloomberg.com/news/articles/2013-07-12/gangs-ruled-prison-as-for-profit-model-put-blood-on-floor
  10. Retrieved on April 1, 2021, from theatlantic.com/magazine/archive/2015/10/the-black-family-in-the-age-of-mass-incarceration/403246/
  11. Retrieved on April 1, 2021, from prisonpolicy.org/reports/pie2020.html
  12. Retrieved on April 1, 2021, from statista.com/statistics/262962/countries-with-the-most-prisoners-per-100-000-inhabitants/
  13. Retrieved on April 1, 2021, from prisonpolicy.org/global/2018.html
  14. Retrieved on April 1, 2021, from prisonpolicy.org/scans/sp/DimRet.pdf
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He is an Associate Professor in the Evaluation and Measurement program within the College of Education, Health and Human Services at Kent State University. He is also the program coordinator for the online Master of Education degree in Research, Measurement, and Statistics.
Dr. Astrid N. Sambolín Morales is an Assistant Professor in Kent State Online’s 100% Online Master of Education degree in Cultural Foundations. She received her PhD in Educational Equity and Cultural Diversity from the University of Colorado Boulder and completed a postdoctoral fellowship at the University of Pennsylvania. Her research provides a more nuanced picture of the agency, resistance, and empowerment enacted by displaced Puerto Rican m(others) in the U.S., and her work was funded by several grants, including the University of Colorado Natural Hazards Center, the BUENO Center for Multicultural Education, the URBAN Research Network, and the NAEd Spencer Foundation.
Felesia McDonald, ’14 is an adjunct instructor in the iSchool, teaching courses in the 100% Online Master of Science in User Experience. McDonald is also the Sr Manager UX Design at Optum, a branch of UnitedHealth Group.