The Transportation Security Administration (TSA) is an agency of the United States Department of Homeland Security (DHS) that has authority over the security of transportation systems within and connecting to the United States. It was created as a response to the September 11 attacks to improve airport security procedures and consolidate air travel security under a combined federal law enforcement and regulatory agency.
The TSA develops key policies to protect the U.S. transportation system, including highways, railroads, bus networks, mass transit systems, ports, pipelines, and intermodal freight facilities. It fulfills this mission in conjunction with other federal, state, local and foreign government partners. However, the TSA's primary mission is airport security and the prevention of aircraft hijacking. It is responsible for screening passengers and baggage at more than 450 U.S. airports, employing screening officers, explosives detection dog handlers, and bomb technicians in airports, and armed Federal Air Marshals and Federal Flight Deck Officers on aircraft.