Which major U.S. legislation was passed in response to the 9/11 attacks?

The USA PATRIOT Act was enacted as a direct response to the September 11, 2001, terrorist attacks. The primary intention of this legislation was to enhance national security and improve the government's ability to investigate and prevent terrorism. It granted law enforcement agencies expanded surveillance capabilities, including the ability to monitor communications and access personal records without a warrant in certain circumstances.

The act was controversial due to concerns over civil liberties, as it expanded the powers of government in ways that some believed infringed on individual rights. Its introduction illustrated the intense focus on counter-terrorism and national security that emerged in American policy after the attacks, reflecting a significant shift in how the government approached domestic security.

Other options, such as the Freedom Act, were related but came later, aiming to reform some of the powers granted by the USA PATRIOT Act. The Defense of Marriage Act and the Healthcare and Education Reconciliation Act do not relate to responses to the 9/11 events and focus instead on issues concerning marriage and healthcare reform, respectively.