It was a morning to remember those we lost nine years ago and a day to remember where we were.
In Lower Manhattan, it was the annual reading of the names of those killed at the World Trade Center.
In Washington, it was President Barack Obama's visit to the Pentagon to make brief remarks in memory of those killed there and in New York and in Pennsylvania, and to call for unity like that which existed after the attacks.
He also urged Americans to devote the day to national service to honor the victims, the same message he delivered in his weekly recorded message.
Again at the Pentagon, it was the start of the annual cross-country bicycle ride from Arlington, Va. to New York City.
In Shanksville, Pa., it was First Lady Michelle Obama and Laura Bush, her White House predecessor, in a show of bipartisan unity to honor the dead of United Airlines Flight 93 and to console their families and friends.
And those were only some of the highest-profile commemorations. Around the nation, there were numerous small remembrances.
It was also the 9/11 anniversary with the the most background noise of controversy in memory, with the simmering controversies over the planned Islamic center near Ground Zero and the Florida pastor's threatened Quran-burning.
In the end, despite all the doubts and quarrels over the causes of, or the U.S. response to, the first Sept. 11, 2001, no one who lived through that day questions that he or she witnessed one of the most powerfully sad and frightening days in U.S. history, the nightmare from which, try as we might, we can't awaken.