After 9/11, which agency was created under new legislation?

The creation of the Department of Homeland Security (DHS) was a significant response to the terrorist attacks on September 11, 2001. This agency was established to consolidate various federal functions related to national security and emergency management under one umbrella to enhance the United States' ability to prevent and respond to domestic threats. The DHS brought together multiple agencies and components, including the Immigration and Naturalization Service, the Coast Guard, and the Secret Service, among others, aiming to improve coordination and communication in matters related to counterterrorism, border security, cyber security, and disaster management.

The other agencies or offices listed were either already in existence prior to 9/11 or were not created specifically as a direct legislative response to the events of that day. Customs and Border Protection and the Drug Enforcement Administration had longer histories, focusing on different aspects of law enforcement and border security, while the Office of Homeland Security and Emergency Management existed in various forms but was not the comprehensive response that the DHS represents. The establishment of DHS marked a pivotal shift in how the U.S. approaches homeland security and terrorism prevention.