It’s been 25 years since the terrorist attacks of Sept. 11, 2001. Many Americans remember the day with clarity: 83% of adults who were born before 2001 – including 93% of those who were 10 or older at the time – say they recall exactly where they were or what they were doing when they heard the news.

This Pew Research Center analysis looks at Americans’ memories of the September 11, 2001, attacks on the World Trade Center and the Pentagon.

We surveyed 5,166 U.S. adults from August 24 to 30, 2026. Everyone who took part in this survey is a member of the Center’s American Trends Panel. The survey represents the views of the full U.S. adult population.

Here are the survey questions used for this analysis, the detailed responses and the survey methodology.

But as the attacks grow more distant, the share of American adults who did not experience that day continues to rise: 10% of adults today were born after 2001 and know about the attacks only through what they have learned from others.

Related: 25 Years After 9/11, a Portrait of Muslim Americans

A majority of these young adults – people who are 18 to 24 today – say they first learned about the attacks in class or through schoolwork (60%), according to a new Pew Research Center survey of 5,166 U.S. adults conducted Aug. 24-30. Smaller shares say they first heard about them from family or friends (16%), through reading or watching something on their own (8%) or some other way (1%). Another 14% aren’t sure how they first learned about the attacks.

The attacks had profound effects on the country. Polls conducted in their wake found widespread fear, anger and sadness, along with overwhelming public support for military action against those responsible.

data essaySep 2, 2021

Twenty years ago, Americans came together – bonded by sadness and patriotism – after the 9/11 terrorist attacks. But a review of public opinion in the two decades since finds that unity was fleeting.

Note: Here are the survey questions used for this analysis, the detailed responses and the survey methodology.

Jocelyn Kiley is director of politics research at Pew Research Center.