All events · After the Wall

United States Immigration Detention and Family Separation

1996–2026 · Americas

Confinement Abduction (Children)

Confined

73,400

The detained population grew from an average daily figure of roughly 8,500 in the mid-1990s, after the mandatory-detention provisions of the 1996 Illegal Immigration Reform and Immigrant Responsibility Act, to about 50,000 in 2019 and to a recorded single-day peak of 73,400 in mid-January 2026 according to the Vera Institute's analysis of ICE data. Vera reports that some 444,900 people were booked into detention between January 2025 and March 2026 and that 152 new facilities were opened. Under the 2018 'zero tolerance' policy at least 2,800 children were separated from parents in the period covered by court order, and the Department of Health and Human Services Inspector General reported in January 2019 that thousands more had been separated before that period than had previously been disclosed.

Share of the population affected

0.30%

of the non-citizen population resident in the United States, 2024

As of 2026-01. The 73,400 figure is the record single-day detention population recorded in mid-January 2026 and continues to move; Vera and TRAC update it from ICE's own releases.

Open on the interactive map →

What happened

Legislation of 1996 made detention mandatory for broad categories of non-citizens facing removal, and the detained population grew steadily thereafter through a network of federal, county and privately run facilities. In 2018 the 'zero tolerance' prosecution policy at the south-west border produced the systematic separation of children from parents; a federal court in Ms L. v. ICE ordered reunification in June 2018, and the Department of Health and Human Services Inspector General reported that the number separated was substantially larger than the government had acknowledged and that no adequate tracking system existed. Detention numbers rose sharply again from 2025: the Vera Institute of Justice, analysing ICE data, recorded a single-day population of 73,400 in January 2026, exceeding all previous peaks, with 152 new facilities opened and roughly 444,900 people booked into detention since January 2025. Conditions, medical care and deaths in custody have been the subject of DHS Office of Inspector General reports and litigation. The atlas already contains Guantanamo and El Salvador's mass incarceration; the largest immigration detention system in the world was absent.

Parties

The United States government detained non-citizens in a nationwide network of federal, county and privately operated facilities pending removal, and in 2018 separated children from parents prosecuted at the border

Disputed

Whether the system constitutes civil confinement incidental to immigration enforcement, as successive US administrations maintain, or arbitrary detention, as UN human rights bodies and litigants have argued; and the true number of children separated in 2017-2018, which the HHS Inspector General found the government could not establish.

The denominator

Migration Policy Institute tabulations of Census Bureau data put the foreign-born population at 50.2 million in 2024, of whom about 25.8 million were naturalised citizens, leaving roughly 24.4 million non-citizens; MPI estimates about 13.7 million of these were unauthorised as of mid-2023. The detention system's own scale is measured differently: the Vera Institute records a record single-day population of more than 73,400 in mid-January 2026, against an average daily population of about 19,000 in the mid-1990s.

The affected figure is a single-day detention count, not the number of people detained over the thirty years covered: annual book-ins have run into the hundreds of thousands, so the cumulative total is in the millions and the ratio understates the system's reach by more than an order of magnitude.

Where the baseline comes from

On the death toll

There is no mass death toll. ICE reports deaths in custody individually, typically in the range of a handful to a few dozen a year, with higher counts in some years; advocacy organisations argue the official figures undercount deaths shortly after release. The harm documented by inspectors general and courts is detention itself, medical neglect and the separation of children rather than lethal violence.

Documented forms of violence

Arbitrary DetentionAbduction of Children

The HHS Inspector General and the federal court in Ms L. v. ICE documented the separation of children from parents; DHS Inspector General reports document detention conditions.

Formal findings

Office of Inspector General, US Department of Health and Human Services (2019) — January 2019 report finding that thousands more children were separated from their parents than the government had reported, and that agencies lacked an adequate system to identify and track separated children — source

Countries touched, on present-day borders

Mexico