The White House has released President Barack Obama's birth certificate, in response to persistent rumours he was not born in the US.
Mr Obama had previously released an official "certification of live birth" showing he was born in Hawaii.
But fringe "birther" theorists have insisted Mr Obama was actually born in his father's native Kenya, making him ineligible to be president.
Recently potential Republican candidate Donald Trump has revived the rumour.
On Wednesday, Mr Obama described the unprecedented move as an effort to rid the US political debate of a distraction, saying he had watched, puzzled and bemused, as the birther conspiracy had built and developed over the past years.
He described the matter as a "sideshow" and its proponents as "carnival barkers".
"We do not have time for this kind of silliness," Mr Obama said. "We've got better stuff to do. I have better stuff to do. We've got big problems to solve, and I'm confident we can solve them, but we're going to have to focus on them - not on this."
The release of Mr Obama's long form birth certificate, which had been stored in a bound volume among the records of the Hawaii Department of Health since his birth in August 1961, comes after years of speculation among conspiracy-minded conservatives.
Under the US constitution, only a "natural born citizen" - a clause widely interpreted to mean born in the US or in some cases to US citizens abroad - is eligible to be president.
Trump's birther hype
The birther conspiracy held that Mr Obama was born in Kenya or in Indonesia, where he lived as a child, or that the birth certificate revealed other unwholesome information about the president.
During the 2008 presidential campaign Mr Obama released a computer print-out of the birth certificate information that is recognised as an official record of his birth - on passport applications, for instance - and Hawaiian public health officials vouched for its authenticity.
But the move did little to quell the birthers, even as most mainstream Republicans have sought to quash the movement, calling it a distraction from substantive policy disagreements.
New York real estate entrepreneur and reality television star Donald Trump, meanwhile, has publicly flirted with a Republican presidential bid in recent weeks, founded in large part by stoking questions about Mr Obama's origins.
And on Wednesday, Mr Trump took credit for forcing Mr Obama's hand.
"I've accomplished something that nobody else has been able to accomplish," Mr Trump told reporters. "He should have done it a long time ago."
The White House released copies of the original birth certificate, with a stamp verifying its authenticity. White House officials said they had been given a waiver by Hawaii public health officials, as the state's policy in general bars release of long-form birth certificates.
The document shows Barack Hussein Obama II was born 4 August 1961 at Kapiolani Maternity and Gynecological Hospital in Honolulu, to Barack Hussein Obama, a 25-year-old student, and Stanley Ann Dunham, 18, and includes the signature of the attending physician.
It remains unclear whether the release of the birth certificate will satisfy the most hard-core birthers.
Joseph Farah, chief executive of birther-orientated website WorldNetDaily.com, said on the site the document "raises as many questions as it answers".
"It is important to remember there are still dozens of other questions concerning this question of eligibility... concerning Barack Obama's parentage, his adoption, his citizenship status throughout his life and why he continues to cultivate a culture of secrecy around his life," he said.