2001: Terrorists hijacked four commercial airplanes. They flew two into the World Trade Center Twin Towers in New York City causing both of them to collapse. One airplane hit the Pentagon in the nation's capital and one plane that was destined for either the White House or the U.S. Capitol crashed into a field in Shanksville, Pennsylvania before it could reach its target. Almost 3,000 people died in the attacks. Memorials have been established in New York City, in Shanksville, and at the Pentagon to remember the victims.

Library of Congress: Within hours of the tragic events of September 11, 2001, Library of Congress staff began to call for and collect a vast array of original materials concerning the attacks on the World Trade Center towers and the Pentagon, and the fate of United Airlines Flight 93 which crashed into the earth at Shanksville, Pennsylvania.Library staff worked in concert with many others to chronicle the events and to collect related material in a wide variety of formats related to 9/11 - for example, photographs, comic book illustrations, magazines, posters, and fine art.

1941: The groundbreaking was held for the Pentagon building, headquarters for the U.S. Department of Defense, the same building that was struck 60 years later on Sept. 11, 2001 when terrorists hijacked four airplanes and turned them into weapons, killing nearly 3,000 innocent people on 9/11.