What is the U.S. Border Patrol?

The U.S. Border Patrol is the federal agency responsible for securing the borders of the United States between official ports of entry. It is part of U.S. Customs and Border Protection, which operates within the Department of Homeland Security. The Border Patrol was established in 1924 to enforce immigration laws along the U.S.-Mexico border in the wake of the Immigration Act of 1924, which sharply restricted immigration to the United States. The agency has expanded substantially since the September 11, 2001 attacks, becoming one of the largest federal law enforcement agencies.

The Border Patrol is headquartered in Washington, D.C., and operates 20 sectors along the U.S. borders with Mexico and Canada, plus along the coasts. The agency employs more than 19,000 Border Patrol agents, with the vast majority assigned to the southern border with Mexico. Sectors along the southwestern border, particularly in Texas, Arizona, and California, are the largest. Border Patrol stations along the U.S.-Canada border and along the coasts are smaller.

The Border Patrol's primary mission is to detect, prevent, and apprehend people attempting to enter the United States illegally between official ports of entry, and to interdict illegal drugs and other contraband moving across the border. Border Patrol agents patrol the border by vehicle, on foot, on horseback, by boat, and by aircraft, and they operate checkpoints on roads leading away from the border. The agency uses technology including ground sensors, surveillance cameras, drones, and integrated fixed towers to monitor large stretches of border.

Apprehension numbers along the southern border have varied dramatically over the decades, generally responding to economic conditions in Mexico and Central America, U.S. enforcement policies, asylum law, and other factors. Apprehensions reached record levels in some years during the early 2000s and again during the 2020s, with several million encounters annually during peaks.

The Border Patrol is distinct from the Office of Field Operations within Customs and Border Protection, which staffs official ports of entry such as airports and land border crossings. People presenting themselves at ports of entry are processed by Office of Field Operations officers; people apprehended between ports are typically handled by Border Patrol agents. The Border Patrol works closely with state and local law enforcement, the Department of Defense (which has at times deployed military personnel to support border operations), and Mexican and Canadian authorities.

Border Patrol policies and tactics have been the subject of ongoing political and legal debate, particularly regarding asylum processing, detention conditions, family separations, and use of force.