Joyous crowds descended on the White House and spontaneously erupted with chants of "USA, USA," as news of Osama bin Laden's death was welcomed by ordinary Americans.
Some brandishing US national flag, they punched the air and sang The Star Spangled Banner, even before the announcement of his death by President Barack Obama in a hurriedly-organized address to the nation.
Starting with just a few dozen people, the crowd quickly built to hundreds pressed against the fence outside the White House, in what rapidly became a party atmosphere as Obama confirmed details.
The news was welcomed by Americans across the country, even though his death was only confirmed shortly before midnight Sunday (US time).
"I'm proud to be an American tonight," Kenneth Specht, a New York fireighter on 9/11, told CNN, paying tribute to the victims of the attacks in New York and Washington.
"Tonight they are first and foremost in our minds," he said.
"Its a long time coming," hotel clerk Becky Grant, 26, at the Fairfield Inn in Ann Arbor, Michigan, told AFP, before asking a passing guest: "Did you hear the news? Bin Laden's been killed."
The Internet, including the Twitter and Facebook social networking websites, were also deluged with reaction to the Al Qaeda leaders death, killed by US forces in Pakistan.
"Finally! I can now sleep tonight knowing this. He was hiding for years and was finally caught and killed. I am so happy right now," said Stewie, on one Yahoo message board.