The US Department of Homeland Security (DHS) was created in response to terrorist attacks that were carried out against the United States on September 11, 2001. Its agencies were tasked with analyzing threats and intelligence, guarding borders and airports, protecting critical infrastructure, and coordinating the nation's response to future emergencies. The Department's aviation assets comprise those of the US Coast Guard and the US Customs and Border Protection Air and Marine Operations (AMO). Today the DHS is responsible for over 200 aircraft operated by the world's largest Coast Guard, and around 240 are flown by the AMO, which is the world's largest aviation and maritime law enforcement organization. Since the creation of the DHS much work has been done within both organizations to integrate, consolidate, and update their varied fleets of fixed wing, rotary wing and remotely piloted unmanned aircraft. This title is fully illustrated with over 120 color photographs and provides insight into the department's creation and the history, aircraft, and operations of the Coast Guard and AMO.