Immigration Enforcement Within the Nation's Borders

Federal, State, and Local Efforts

Immigration Enforcement Within the United States

Quick Summary

This inventory of immigration enforcement policies and programs within U.S. borders highlights areas of cooperation among federal, state, and local governments. Enforcement activities are presented on five maps illustrating that they are dispersed widely across the country. This brief, the first in a series, will be followed by examinations of border management programs and other immigration issues.


The enforcement of U.S. immigration laws is commonly thought of as a border activity, yet activities related to immigration enforcement extend across all states and territories. The federal government has the primary responsibility for enforcing immigration laws, and such efforts have historically been concentrated along the U.S. borders and in states with the largest numbers of unauthorized immigrants. In recent years, however, these federal activities have spread widely into the nation’s interior, and are felt in many states and localities. 

At the same time as these enforcement efforts have become so widely dispersed, collaboration between different levels of government has increased as the federal government has partnered with state and local law enforcement more routinely over the past decade. Currently, there are joint efforts in all 50 states and the District of Columbia. This cooperation occurs both through formal channels, such as task forces and partnerships, and informal mechanisms, such as local police informing federal immigration authorities when they suspect a person is in the country illegally. 

Because these activities and partnerships have become more common and are under greater scrutiny, the nation is at a critical juncture regarding the enforcement of immigration laws. This brief offers context for federal, state, and local policymakers who make decisions on such activities by providing an overview of key federal immigration agencies, offices, and enforcement efforts within the United States as well as certain state activities. Understanding these enforcement efforts will help policymakers at all levels of government develop a broader and more complete picture of how their choices could affect the states, including potential impacts on state and local budgets and economies. 

This is not meant to be an exhaustive accounting of all federal and joint activities or state laws regarding immigration enforcement; instead, it focuses on important examples. The Pew Charitable Trusts takes no position on federal, state, or local immigration-related laws or policies.