The United States Border Patrol (USBP) is a federal law enforcement agency within U.S. Customs and Border Protection (CBP), tasked with patrolling nearly 6,000 miles of Mexican and Canadian land borders and over 2,000 miles of coastal waters to prevent illegal entries, terrorism, and smuggling.

Its priority mission is to detect and prevent terrorists and their weapons from entering the U.S., while interdicting undocumented migrants, smugglers, and contraband between ports of entry through surveillance, checkpoints, and patrols.

Established in 1924, it employs over 21,000 agents who operate in diverse terrains using vehicles, boats, horses, sensors, and other tools to secure the borders.