In this interactive lesson, students learn about September 11, 2001, and how the deadliest terror attacks in U.S. history changed the country and the world. Using videos, text, and images, students explore the day’s tragic events, how the nation and world responded, and how Americans remember 9/11 and the thousands who died.

Explore what happened on September 11, 2001, the day of the deadliest terror attacks in U.S. history. Learn how four airplanes were used as weapons to target iconic American buildings and how brave individuals tried to thwart the attacks.

Learn how the world changed after September 11, 2001. The United States experienced immediate disruption after the attacks, with economic losses and changes to everyday life. The War on Terror began one month after the attacks, and new government policies and intelligence programs led to domestic and international changes and consequences.

Learn how September 11, 2001, is remembered at Ground Zero, the Pentagon, and Shanksville and in communities across the country through memorials that honor those who died and that create spaces for contemplation and remembrance. The United States now observes September 11 as a National Day of Service and Remembrance, a time when the nation collectively remembers the day’s tragedy and the acts of courage shown on September 11 and in the days that followed.