Barack Obama won the Presidency and made history on a steady message of bringing change to a country that has been hungering for it.

The first black to be elected US President, Mr Obama ran a nearly flawless campaign and proved to be a cool customer under fire on the campaign trail and during three head-to-head debates with defeated Republican John McCain.

"It's been a long time coming, but tonight, because of what we did on this day, in this election, at this defining moment, change has come to America," Mr Obama told cheering supporters in Chicago after his victory.

He ran for President during the best possible conditions for a politician running against the incumbent party - a country saddled with two wars and teetering on the brink of a recession, including a Wall Street meltdown that amounted to an October surprise.

"He won because he was the Democratic nominee in a year that was just perfect for Democrats," said Larry Sabato, a political science professor at the University of Virginia.

President George W. Bush was not on the ballot but it sure seemed like it.

Mr Obama linked Mr McCain to Mr Bush at every turn, even though the two Republicans are not particularly fond of each other and Mr McCain had broken with Mr Bush on several important issues.

It did not matter. Mr Obama had only to keep bringing up the fact that the Arizona senator had voted with Mr Bush 90 per cent of the time.

Mr Obama was able to straddle the middle ground, managing to escape Mr McCain's attacks on his liberal voting record as a senator from Illinois, and raised vast sums of money for television advertisements that essentially turned him into an iconic figure.

"He ran a perfect, nearly gaffe-free campaign and he stayed on an absolutely pitch-perfect message," said Democratic strategist Liz Chadderdon.

Mr Bush's popularity rating under 30 per cent was a heavy drag on Mr McCain. Despite an improving security picture in Mr Bush's Iraq war and a rapid response by the Bush administration to the financial crisis, Americans were ready to turn the page.

"Obama just pounded on this theme that we just can't afford four more years," said Democratic strategist Jim Duffy. "I think Bush was a huge millstone."

Mr McCain, 72, ran about as well as a Republican could have in a toxic environment for his party. He won large segments of the country but fell short in the battleground states that were decisive.

"We fought as hard as we could and though we fell short, the failure is mine, not yours," Mr McCain told supporters at a Phoenix hotel. "I wish the outcome was different, my friends. The road was a difficult one from the outset."

Mr McCain was riding a lead in the national polls in September until Wall Street began falling apart, exposing the weakness of the economy. His response was not as surefooted as Mr Obama's, and it cost him.

"The environment was loaded against him, and even with the toxic environment for Republicans, he made it very close until the financial meltdown. That's what finally created the daylight between the two candidates that lasted until election day," said Republican pollster Whit Ayres.

Some will question whether Mr McCain should have chosen the inexperienced Alaska Gov. Sarah Palin as his vice Presidential running mate.

The news media's vetting of Ms Palin drew negative headlines for weeks and some conservatives were sharply critical of Mr McCain's selection of her over other more experienced Republican leaders.

Mr McCain ignored the critics.

In his concession speech in Phoenix, he called Ms Palin "one of the best campaigners I've ever seen," and an "impressive new voice in our party for reform" - a statement likely to be fodder for speculation about the next Presidential election - in 2012.

Who is Barack Obama?

Age: 47

Birthdate: August 4, 1961

Birthplace: Honolulu, Hawaii

Education: Columbia University; Harvard Law School

Wife: Michelle Robinson

Children: Two daughters, Sasha and Mailia

Religious affiliation: United Church of Christ

Family

Barack Obama was born in Hawaii to a Kenyan father and a white American mother. His father, Barack Obama Sr, married his mother, Ann Dunham, while studying at the University of Hawaii. The couple separated two years after Mr Obama was born. His father ultimately returned to Kenya, where he became a noted economist. He died in a car accident in 1982.

Mr Obama's mother's second marriage was to an Indonesian man named Lolo Soetoro. The family moved to Indonesia and Mr Obama remained there until he was 10 when he moved back to Hawaii and lived with his grandparents while studying on a scholarship at the elite Punahou Academy.

He has seven half brothers and sisters in Kenya from his father's other marriages, and a half-sister, Maya Soetoro-Ng, from his mother's second marriage.

Career

After finishing college in 1983, Mr Obama worked for a New York financial consultant and a consumer organisation. He landed a job in Chicago in 1985 as an organiser for Developing Communities Project, a church-based group seeking to improve living conditions in poor neighbourhoods.

Three years later, Mr Obama left to go to Harvard Law School, where he became the first black President of the law review. He worked as a summer associate at the Sidley Austin law firm in Chicago, where he met his future wife. After graduation from Harvard in 1991, Mr Obama practised civil rights law at a small firm in Chicago, then became a lecturer in constitutional law at the University of Chicago in 1993.

Elective office

Mr Obama won a seat in the Illinois state Senate in 1996. During his time in the legislature, he worked on welfare and ethics legislation, as well as a measure requiring electronic recording of police interrogations and confessions in homicide investigations.

Mr Obama won a heavily contested US Senate seat in 2004, carrying 53 per cent of the Democratic primary vote in an eight-candidate race. He easily won the general election. In the Senate he compiled a liberal voting record, but was one of the few Democrats to back a measure on class-action lawsuits. He opposed the appointment of Chief Justice John Roberts and Justice Samuel Alito to the US Supreme Court.

The non-partisan National Journal ranked him as the most liberal member of the Senate early this year based on his voting record in 2007. He was ranked 10th most liberal in 2006 and 16th most liberal in 2005.