September 11 Attacks

On the morning of September 11, 2001, 19 al-Qaeda hijackers seized four commercial airliners and turned them into weapons. Two struck the Twin Towers of the World Trade Center in lower Manhattan; one hit the Pentagon in Arlington, Virginia; a fourth, its passengers having staged a revolt against the hijackers, plunged into a field near Shanksville, Pennsylvania. By midmorning both 110-story towers had collapsed. Nearly 3,000 people died — the deadliest terrorist attack in history.

The attacks transformed American life and foreign policy overnight. Congress authorized military force and passed the USA PATRIOT Act within weeks. The United States invaded Afghanistan in October 2001 to dismantle al-Qaeda and remove the Taliban government that had harbored it. A new Department of Homeland Security reorganized the federal government's security apparatus, airport screening was federalized, and National Security Agency surveillance powers expanded in ways that sparked legal controversy for a generation.

The cultural wound ran as deep as the political one. At the field in Shanksville, the words "Let's roll" — spoken by passenger Todd Beamer before the passengers rushed the cockpit — became a rallying cry. Ground Zero was rebuilt over more than a decade into One World Trade Center and a memorial of two vast reflecting pools, each occupying a tower's former footprint, inscribed with the names of every victim.

The 9/11 Commission, established in 2002 to examine intelligence and security failures, produced one of the most-read government documents in American history. The attacks set in motion nearly 20 years of war in Afghanistan and provided the political context for the 2003 invasion of Iraq. They reshaped immigration policy, civil liberties law, and the architecture of the federal government. For Americans who lived through them, the events of that September morning remain the defining trauma of the 21st century.