A written request that a local jail or other law enforcement agency detain an individual for an additional 48 hours after his or her ordinary release date in order to provide ICE agents extra time to decide whether to take the individual into federal custody for removal purposes.

A 1996 law that established three- and ten-year bars on re-entry for immigrants who accrue “unlawful presence” in the U.S., leave the country, and then want to re-enter the country lawfully. Generally, an immigrant who enters the U.S. without authorization, or who overstays a period of authorized admission, will be deemed to have accrued unlawful presence. Individuals who accrue more than 180 days, but less than one year, of unlawful presence are barred from re-entering the U.S. for three years; those who accrue more than one year of unlawful presence are barred for ten years.

Also known as the Johnson-Reed Act, this was legislation that blocked immigration from Asia, set quotas on the number of immigrants from the rest of the Eastern Hemisphere and provided funding to carry out other long-established immigration restrictions. The measure set a total annual immigration quota of 165,000 for countries outside of the Western Hemisphere—an 80-percent reduction from pre-WWI levels. It was the need to enforce this legislation that triggered the creation of the U.S. Border Patrol.

First introduced in 1989 by Senator Ted Kennedy, this legislation reformed the Immigration and Nationality Act of 1965 by increasing overall immigration to allow 700,000 immigrants to come to the U.S. during the first year of enactment and 675,000 annually thereafter. This act also established family-based immigration visas, a diversity lottery, and the first set of employment-based visas.

The U.S. law enforcement agency principally responsible for the enforcement of customs and immigration laws. While the agency’s immigration enforcement activities gain the most media attention, ICE also conducts a wide range of customs operations, including drug seizures, fraudulent product seizures, and searches for illegally transported antiquities and child pornography, to name a few.

Signed into law by President Lyndon Johnson, this was the first major immigration legislation in nearly half a century. It abolished the National Origins Formula, established in 1924, which set limits on how many immigrants could enter the U.S. from various regions of the world, including Asia, Southern and Eastern Europe, and other non-Western European areas. These limits were widely seen as discriminatory and were described by the U.S. State Department as formulas that were set “to preserve the ideal of American [Northwestern European] homogeneity.” Widespread awareness of the discriminatory nature of the National Origins Formula and support for its repeal are often linked to the rise of the Civil Rights Movement.

This was the first major immigration legislation since the Immigration and Nationality Act of 1965. This law made it illegal to knowingly hire undocumented immigrants by establishing financial penalties for doing so, strengthened border security, and granted legal status to nearly 3 million immigrants who were in the country illegally and had arrived prior to January 1, 1982.