Haddal, C. C. (2010). Border Security: Key Agencies and Their Missions. Congressional Research Service. 7-5700. Washington, DC.After the reorganization of federal agencies precipitated by the creation of the Department of Homeland Security (DHS), there are now four main federal agencies charged with securing the United States’ borders: the U.S. Customs and Border Protection (CBP), which patrols the border and conducts immigrations, customs, and agricultural inspections at ports of entry; the U.S. Immigrations and Customs Enforcement (ICE), which investigates immigrations and customs violations in the interior of the country; the United States Coast Guard, which provides maritime and port security; and the Transportation Security Administration (TSA), which is responsible for securing the nation’s land, rail, and air transportation networks.