The United States Department of Homeland Security, which is commonly referred to as DHS or simply “homeland security,” was formed in response to the terrorist attacks of September 11, 2001. The National Strategy for Homeland Security and the Homeland Security Act of 2002 called for the formation of the DHS, which was established to provide a unifying agency for the many national organizations that serve to secure the United States. The formation of the DHS constituted the largest governmental reorganization in the past 50 years.

DHS was officially formed on November 25, 2002 and is a Cabinet department of the federal government. The U.S. Department of Homeland Security coordinates many resources and agencies at federal, state, and local levels in order to develop a comprehensive system that connects different agencies and various levels of government.

The stated vision of the DHS is “Preserving our freedoms, protecting America…we secure our homeland.” The mission of the DHS includes preventing terrorist attacks, responding to national security threats, reducing America’s vulnerability to terrorism, ensuring safe and secure borders, welcoming lawful immigrants and tourists and promoting commerce. The stated strategic goals of the DHS include awareness, prevention, protection, response, recovery, service and organizational excellence.

The major components that make up the Department of Homeland security include:

• Directorate for National Protection and Programs
• Directorate for Science and Technology
• Directorate for Management
• Office of Health Affairs
• Office of Intelligence and Analysis
• Office of Operations Coordination
• Federal Law Enforcement Training Center
• Domestic Nuclear Detection Office
• Transportation Security Administration (TSA)
• United States Customs and Border Protection (CBP)
• United States Citizenship and Immigration Services (USCIS)
• United States Immigration and Customs Enforcement (ICE)
• United States Coast Guard * Federal Emergency Management (FEMA)

Tom Ridge, the former governor of Pennsylvania, was appointed as the first secretary of the DHS by President George Bush. Ridge resigned from his post on November 30, 2002, and federal judge Michael Chertoff was sworn in as his replacement on February 15, 2005. Chertoff serves as the current secretary of the Department of Homeland Security. DHS is headquartered in the Nebraska Avenue Complex in Washington D.C., which is a former naval facility. As of 2007, DHS was comprised of over 200,000 employees and had an annual budget of $44.9 billion.