The United States Customs Service was an agency of the U.S. federal government that collected import tariffs and performed other selected border security duties. In March 2003, as a result of the homeland security reorganization, most of the U.S. Customs Service was merged with the border elements of the Immigration and Naturalization Service, including the entire U.S. Border Patrol and former INS inspectors, together with border agriculture inspectors, to form U.S. Customs and Border Protection, a single, unified border agency for the U.S. The investigative office of U.S. Customs was split off and merged with the INS investigative office and the INS interior detention and removal office to form Immigration and Customs Enforcement, which, among other things, is responsible for interior immigration enforcement. The United States Customs Service had three major missions: collecting tariff revenue, protecting the U.S. economy from smuggling and illegal goods, and processing people and goods at ports of entry.