What significant event happened on September 11, 2001, in the United States?

The event that occurred on September 11, 2001, was a series of coordinated terrorist attacks orchestrated by the extremist group al-Qaeda. On that day, four commercial airliners were hijacked. Two of these planes were flown into the Twin Towers of the World Trade Center in New York City, leading to their eventual collapse. Another plane was crashed into the Pentagon in Arlington, Virginia, which serves as the headquarters of the United States Department of Defense. The fourth plane, United Airlines Flight 93, was headed towards a target in Washington, D.C., but passengers attempted to retake control, resulting in the plane crashing in a field in Pennsylvania.

This tragic day resulted in significant loss of life, with nearly 3,000 people killed and thousands more injured. The attacks led to a major shift in U.S. domestic and foreign policy, including the War on Terror, increased security measures, and the establishment of the Department of Homeland Security. The ramifications of that day are still felt to this day, influencing various aspects of American society and international relations.

The other events listed do not correspond to September 11, 2001, and reflect moments that had their own significance in U.S. history. The economic recession relates to a