September 11 attacks transformed American security and daily life

The September 11, 2001 attacks changed the United States deeply and permanently. Thousands of people died, and the country felt immediate fear. In surveys taken after the attacks, nearly three quarters of Americans said they were worried about another attack. About half said they felt more afraid or more distrustful than before.

The government responded quickly. It created new agencies, including the Department of Homeland Security and the TSA, which now screens passengers at airports. Police departments also received military equipment. A new law called the Patriot Act gave the government greater power to monitor people.

Ten years later, 61% of Americans still said the country had changed in a major way. For 38% of people, 9/11 was the most important event of their personal lives.