<P> Ridge began his duties as OHS director on October 8, 2001 . </P> <P> According to Peter Andreas, a border theorist, the creation of DHS constituted the most significant government reorganization since the Cold War, and the most substantial reorganization of federal agencies since the National Security Act of 1947, which placed the different military departments under a secretary of defense and created the National Security Council and Central Intelligence Agency . DHS also constitutes the most diverse merger of federal functions and responsibilities, incorporating 22 government agencies into a single organization . </P> <P> The Department of Homeland Security was established on November 25, 2002, by the Homeland Security Act of 2002 . It was intended to consolidate U.S. executive branch organizations related to "homeland security" into a single Cabinet agency . The following 22 agencies were incorporated into the new department: </P> <Table> <Tr> <Th> Original agency </Th> <Th> Original department </Th> <Th> New agency or office after transfer </Th> </Tr> <Tr> <Td> U.S. Customs Service </Td> <Td> Treasury </Td> <Td> U.S. Customs and Border Protection U.S. Immigration and Customs Enforcement </Td> </Tr> <Tr> <Td> Immigration and Naturalization Service </Td> <Td> Justice </Td> <Td> U.S. Customs and Border Protection U.S. Immigration and Customs Enforcement U.S. Citizenship and Immigration Services </Td> </Tr> <Tr> <Td> Federal Protective Service </Td> <Td> General Services Administration </Td> <Td> National Protection and Programs Directorate </Td> </Tr> <Tr> <Td> Transportation Security Administration </Td> <Td> Transportation </Td> <Td> Transportation Security Administration </Td> </Tr> <Tr> <Td> Federal Law Enforcement Training Center </Td> <Td> Treasury </Td> <Td> Federal Law Enforcement Training Center </Td> </Tr> <Tr> <Td> Animal and Plant Health Inspection Service (part) </Td> <Td> Agriculture </Td> <Td> U.S. Customs and Border Protection </Td> </Tr> <Tr> <Td> Office for Domestic Preparedness </Td> <Td> Justice </Td> <Td> Responsibilities distributed within FEMA </Td> </Tr> <Tr> <Td> Federal Emergency Management Agency </Td> <Td> none </Td> <Td> Federal Emergency Management Agency (FEMA) </Td> </Tr> <Tr> <Td> Strategic National Stockpile National Disaster Medical System </Td> <Td> Health and Human Services </Td> <Td> Returned to HHS, July, 2004 </Td> </Tr> <Tr> <Td> Nuclear Incident Response Team </Td> <Td> Energy </Td> <Td> Responsibilities distributed within FEMA </Td> </Tr> <Tr> <Td> Domestic Emergency Support Team </Td> <Td> Justice </Td> <Td> Responsibilities distributed within FEMA </Td> </Tr> <Tr> <Td> National Domestic Preparedness Office </Td> <Td> Justice (FBI) </Td> <Td> Responsibilities distributed within FEMA </Td> </Tr> <Tr> <Td> CBRN Countermeasures Programs </Td> <Td> Energy </Td> <Td> Science & Technology Directorate </Td> </Tr> <Tr> <Td> Environmental Measurements Laboratory </Td> <Td> Energy </Td> <Td> Science & Technology Directorate </Td> </Tr> <Tr> <Td> National Biological Warfare Defense Analysis Center </Td> <Td> Defense </Td> <Td> Science & Technology Directorate </Td> </Tr> <Tr> <Td> Plum Island Animal Disease Center </Td> <Td> Agriculture </Td> <Td> Science & Technology Directorate </Td> </Tr> <Tr> <Td> Federal Computer Incident Response Center </Td> <Td> General Services Administration </Td> <Td> US - CERT, Office of Cybersecurity and Communications National Programs and Predaredness Directorate </Td> </Tr> <Tr> <Td> National Communications System </Td> <Td> Defense </Td> <Td> Office of Cybersecurity and Communications National Programs and Predaredness Directorate </Td> </Tr> <Tr> <Td> National Infrastructure Protection Center </Td> <Td> Justice (FBI) </Td> <Td> Office of Operations Coordination Office of Infrastructure Protection </Td> </Tr> <Tr> <Td> Energy Security and Assurance Program </Td> <Td> Energy </Td> <Td> Office of Infrastructure Protection </Td> </Tr> <Tr> <Td> U.S. Coast Guard </Td> <Td> Transportation </Td> <Td> U.S. Coast Guard </Td> </Tr> <Tr> <Td> U.S. Secret Service </Td> <Td> Treasury </Td> <Td> U.S. Secret Service </Td> </Tr> </Table>

When was the department of homeland security established