Homeland Security Act

Homeland Security Act, U.S. legislation signed into law by President George W. Bush on November 25, 2002, that established the Department of Homeland Security (DHS) as a new department in the executive branch of the government and established a number of measures aimed at protecting the national security of the United States. The act was drafted in the aftermath of the September 11 attacks in 2001, when defending the United States against terrorist attacks and responding to large-scale emergencies had rapidly emerged as top priorities for the government.

Until the passage of the Homeland Security Act, the U.S. security apparatus had been dispersed across a wide range of federal agencies and the military. In addition to creating an entirely new federal government organization with its own mandate, a cabinet-level secretary, and more than 180,000 employees at the time of its founding, the Homeland Security Act placed a number of existing agencies beneath the larger umbrella of the DHS, which took on responsibilities ranging from infrastructure protection and chemical, biological, radiological, nuclear, and related countermeasures to border and transportation security, emergency preparedness and response, and coordination with other parts of the federal government, with state and local governments, and with the private sector.