What major event occurred on September 11, 2001, in the United States?

On September 11, 2001, the United States experienced a significant and devastating terrorist attack. This event is marked by the coordinated hijacking of four commercial airplanes by terrorists associated with the extremist group al-Qaeda. Two of these planes were flown into the Twin Towers of the World Trade Center in New York City, leading to their collapse, while a third plane struck the Pentagon in Arlington, Virginia. The fourth plane, United Airlines Flight 93, was headed towards a likely target in Washington, D.C., but passengers attempted to regain control and it ultimately crashed in Pennsylvania.

This act of terrorism resulted in the deaths of nearly 3,000 people and caused extensive destruction, profoundly impacting U.S. domestic and foreign policy, national security measures, and global attitudes towards terrorism. The 9/11 attacks are commemorated as a pivotal moment in American history, leading to the War on Terror and significant changes in national defense and counter-terrorism laws.

The other options, such as an earthquake, a presidential election, or a financial crisis, all represent significant events in their own right, but they do not capture the historical importance and implications of the terrorist attack on September 11, 2001. This event fundamentally altered the course of U