The Transportation Security Administration (TSA) was established in response to the tragic events of September 11, 2001. This led to the formation of a robust security task force for the United States on November 19, 2001.
Initially, the TSA ensured that all checked baggage at airports was screened by aviation security staff and specialist x-ray machines. In 2002, it reinforced cockpit doors on commercial aircraft and introduced explosive trace detection for baggage. By 2003, the TSA became part of The Department of Homeland Security.
In response to ongoing threats, including an attempted shoe bombing in 2006, the TSA introduced measures such as shoe removal during screening processes. The agency also deployed air marshals on select US flights to assist crews in life-threatening situations. "Federal Air Marshals are deployed to assess, address and mitigate varying potential risks and threats to transportation and travelers," stated the TSA.