New American Immigration Council Report on Immigration Detention Expansion

When President Trump took office in January 2025, there were roughly 40,000 people being held in immigration detention. By the start of December, that number had risen by almost 75 percent, with nearly 66,000 people held in immigration detention across the United States and the system reportedly capable of holding 70,000 people on any given day — the highest level in history.

This report aims to document the historic expansion of detention under the Trump administration. It details not only the policy changes which have led to ICE detention reaching the highest level on record, but also their impact on the individuals who have found themselves locked into it. The growth in immigration detention, and the spectacle which has accompanied the construction and use of new facilities — coupled with the near-elimination of any transparency into the operation and use of those facilities — is the backbone of President Trump’s mass deportation efforts.

As this report reveals, rather than focusing on serious public safety threats and flight risks, the Trump administration is primarily using detention to pressure people into giving up their chance to remain in the United States.