Domestic response

Following the attacks, President Bush's job approval rating soared to 86%. On September 20, 2001, the U.S. president spoke before the nation and a joint session of the United States Congress, regarding the events of that day, the intervening nine days of rescue and recovery efforts, and his intent in response to those events. In addition, the highly visible role played by New York City mayor Rudy Giuliani won him high praise nationally and in New York. Many relief funds were immediately set up to assist victims of the attacks, with the task of providing financial assistance to the survivors of the attacks and to the families of victims. By the deadline for victim's compensation, September 11, 2003, 2,833 applications had been received from the families of those who were killed.

Contingency plans for the continuity of government and the evacuation of leaders were also implemented almost immediately after the attacks. Congress, however, was not told that the United States was under a continuity of government status until February 2002.

Within the United States, Congress passed and President Bush signed the Homeland Security Act of 2002, creating the Department of Homeland Security, representing the largest restructuring of the U.S. government in contemporary history. Congress also passed the USA PATRIOT Act, stating that it would help detect and prosecute terrorism and other crimes. Civil liberties groups have criticized the PATRIOT Act, saying that it allows law enforcement to invade the privacy of citizens and eliminates judicial oversight of law-enforcement and domestic intelligence gathering. The Bush Administration also invoked 9/11 as the reason to initiate a secret National Security Agency operation, "to eavesdrop on telephone and e-mail communications between the United States and people overseas without a warrant."