Post-9/11 America refers to the period following the terrorist attacks on September 11, 2001, which fundamentally altered U.S. domestic and foreign policies, as well as societal attitudes. The events of 9/11 led to increased security measures, the initiation of the War on Terror, and significant changes in public perception towards issues like immigration, civil liberties, and national security. This era marked a new chapter in American history characterized by both heightened fear and increased government involvement in the lives of citizens.