The loved ones gathered again in lower Manhattan for moments of silence and the peals of the bells. They paid tribute to those they lost 20 years earlier and listened as Bruce Springsteen sang about memory and loss.

In Pennsylvania, hundreds gathered in a clearing where a hijacked plane had crashed to hear a former president honor their relatives’ sacrifice. In Chicago, firefighters too young to remember Sept. 11 climbed thousands of steps to honor emergency responders who didn’t live past it. In Nebraska, children sat on the shoulders of their parents and waved American flags to honor the victims of a tragedy that, to them, has only been history.

For two decades, Americans have mourned the attacks of Sept. 11, 2001, that killed nearly 3,000 people, a loss so deep it shook the United States to its core. But even as time has passed, and the horrific day has moved from fresh memory into the chronicles of history, the people who gathered across the country and the globe said the wounds from 9/11 have remained fresh.