Created in 2003 from the former US Customs Service (Homeland Security Act); accounts for approximately one-fifth of the DHS's total budget. Budget is greater than the entire defense budget of Colombia, Taiwan, or Iran. It employs 52,000 people, including 17,000 border patrol agents, 1000 air and marine agents, and 22,000 port inspectors.
...Department of Homeland Security officials have reconstituted an internal affairs unit at Customs and Border Protection, one of the largest federal law enforcement agencies, overseeing both border agents and customs officers.
When the Homeland Security Department was created in 2003, the internal affairs unit was dissolved and its functions spread among other agencies...
(NY Times, "Border Agents, Lured by the Other Side"--27 May 2008)