Americans have streamed to the site of the World Trade Centre and the gates of the White House to celebrate the death of Osama bin Laden - cheering, waving flags and belting out the national anthem.
Ground Zero, more familiar these past 10 years for bagpipes playing Amazing Grace and solemn speeches and arguments over what to build to honour the September 11 dead, became, for the first time, a place of revelry on Monday.
Lisa Ramaci, a New Yorker whose husband was a freelance journalist killed in the Iraq war, said: "We've been waiting a long time for this day. I think it's a relief for New York tonight just in the sense that we had this 10 years of frustration just building and building, wanting this guy dead, and now he is, and you can see how happy people are."
In Times Square, dozens stood together on a clear spring night and broke into applause when a New York Fire Department vehicle drove by, flashed its lights and sounded its siren. A man held an American flag, and others sang The Star-Spangled Banner.
In Washington, in front of the White House, a crowd began gathering before President Barack Obama addressed the nation late on Sunday night to declare: "Justice has been done." The crowd grew, and within half an hour had filled the street in front of the White House and begun spilling into nearby Lafayette Park.
The celebrations came together after Americans began hearing about the death of bin Laden from bulletins on television, texts and calls from family and friends, and posts on social networking sites.
Later, US secretary of state Hillary Clinton warned al Qaida that the killing of Osama bin Laden in Pakistan proves the terrorist network cannot defeat the United States.
Mrs Clinton urged members of the group to abandon violence and rejoin society following bin Laden's death, which she described as a "milestone" in the war on terrorism.
She stressed that the "battle to stop al Qaida and its syndicate of terror" is not over, but stressed that the operation to find and kill bin Laden nearly a decade after the 9/11 terror attacks showed the US would never abandon its pursuit of justice.
Mrs Clinton said the US would continue to boost its counter-terrorism co-operation with other nations, including Pakistan.