KEY POINTS:
Barack Obama called his election as president of America the "defining moment change has come to America", calling for "a new spirit of patriotism, of responsibility" to address the greatest challenges "of our lifetime".
Obama was elected the 44th president of the United States - and the first black Commander-in-Chief in the country's history in a crushing victory of his Republican opponent.
Despite the elation of his victory, he reminded supporters of the real work that lay ahead.
"This victory alone is not the change we seek," Obama said. "It is only the chance for us to make that change. And that cannot happen if we go back to the way things were.
"It can't happen without you, without a new spirit of service, a new spirit of sacrifice.
"Even as we celebrate tonight, we know the challenges that tomorrow will bring are the greatest of our lifetime - two wars, a planet in peril, the worst financial crisis in a century."
The 47-year-old, who secured wins in all the crucial states, including Ohio, Pennsylvania and Colorado, addressed a crowd of supporters in Chicago telling them the result was a "defining moment" for the United States.
He said: "If anyone out there still doubts anything is possible in this country... tonight is your answer."
The result was called at about 5pm New Zealand time and John McCain conceded defeat shortly afterwards, praising Obama.
Obama, who needed 270 electoral college votes to win, now has 338 by CNN's calculation - a massive victory.
President George W Bush has called Obama to offer his congratulations and invite him to the White House.
McCain, speaking to a crowd in his home state of Arizona, said: "We have come to the end of a long journey. They have spoken and they have spoken clearly."
To boos from some in the crowd, he said he had called to congratulate Obama.
McCain said Obama had earned his respect for his perseverance in the nearly two-year campaign.
He added: "We fell short but the failure is mine not yours."
Obama has capped off his historic victory with wins in several Western states.
He defeated McCain in California, Oregon and Washington state - and tossed in New Mexico, Colorado, Hawaii and Nevada.
Obama had earlier defeated McCain both in Democratic strongholds in the East and Midwest and also in battleground states that had held the last hopes of a Republican victory.
According to CNN's exit polls, Obama won 55 per cent of the male vote and 58 per cent of the female vote.
As far as age is concerned, Obama brought the young out to vote, attracting 62 per cent of the 18-29 year-old vote while his opponent attracted 37 per cent.
In the 30 to 44 age group, Obama attracted 59 per cent of the vote, while McCain won 37 per cent. And for those aged between 45 and 64, 54 per cent voted for Obama, while 42 per cent voted for McCain.
There was a similar trend in the 65 and older camp with 56 per cent voting for Obama, while 42 per cent voted for McCain.
The New York Times has put his victory down to America wanting change.
In an article posted just minutes after major TV networks called the election in Obama's favour, the Times contrasted a the 47 year-old senator from Illinois with the 72 year-old former prisoner of war.
"Mr McCain's campaign was eclipsed by an opponent who was nothing short of a phenomenon, drawing huge crowds epitomised by the tens of thousands of people who turned out to hear Mr. Obama's victory speech in Grant Park in Chicago," the Times said.
Chris Cillizza in the Washington Post has said Obama has re-shaped the electoral map with a shake-up of the status quo.
"Obama's victory was both broad and deep; he won hotly contested states in every corner of the country from New Hampshire in the Northeast, and likely Virginia in the South to Ohio in the Midwest and New Mexico in the West."
Youngest president
At 47, Obama will become the fifth youngest president in US history. The age gap between he and McCain, 72, was a critical factor in his campaign of "change", and his push to lead the US in a new direction.
The US$641m raised during his presidential campaign smashed the previous record and was built largely around 3.2 million small online donations of under US$200 each, from donors across the globe.
Particularly popular among young and black voters, Obama's campaign focused on tax, energy and foreign affairs.
Who is Obama?
Born in Hawaii in 1961, Obama graduated from Columbia University and Harvard Law School and served as a civil rights lawyer before entering fulltime politics in the Illinois senate in 1997.
He was elected to the US Senate in 2004.
Obama was largely raised by his mother Ann Dunham and his maternal grandmother Madelyn Lee Payne Dunham.
His parents split when he was two-years-old with his father later returning to live in his Kenyan homeland. He died in a car accident in 1982.
In 1989 Obama met Michelle Robinson while working as a summer associate at a Chicago law firm. The couple became engaged in 1991 and married the following year. They have two children, Malia Ann born in 1998 and Natasha born in 2001.
In December 2007Money magazine estimated the Obama family's net worth at US$1.3m
Obama has written three books including The Audacity of Hope and Dreams From My Father.
- NZ HERALD STAFF
