Sept. 11, 2001, was marked by the largest foreign attack on U.S. soil in modern history, when some 3,000 lives were lost.
The impact was widespread and enduring, a shared national experience unlike any since President John F. Kennedy's 1963 assassination. A 2021 Pew survey found that 93% of those age 30 and older could remember exactly what they were doing when they learned that first one plane, and then a second, had crashed into the World Trade Center's twin towers.
Some 238 mothers in Minnesota would never forget what they were doing that day: bringing children into a country forever changed.
Justin Anderson of Monticello, Minn., was around 5 years old when his parents told him about the day of his birth in the wee hours of Sept. 11.
"They said the nurses came in and told them to turn the TV on," Anderson said. "The nurses were watching the TV. They were watching the TV. Everybody was in shock."
These "9/11 babies" knew nothing of life before the attacks. But since others can't help but react to learning of their notable birthday, they became repositories for how other people feel about the historic event.
For most Americans, 9/11's impact was more a mind-set shift than a material change to their lifestyle. After the attacks, many felt anxious and depressed and feared more foreign assaults. The U.S. military launched its Global War on Terror, invading Afghanistan and Iraq.