KEY POINTS:
As Americans suck in a nervous or exhilarated breath, wondering whether they have done the right thing electing a first-term senator their commander-in-chief, they can take comfort in the fact that he had to slay two doughty dragons to get there.
Barack Obama is deceptively languid and unruffled. He may recall the kid who could cruise his way to the top of the class, but somewhere underneath is the diligent swot who double-checks his facts, thinks through the options and works at it.
Over the past year as he has gone from upstart insurgent to disciplined Obamaster, the inner tidiness has become more apparent. His victories over Hillary Clinton and John McCain were a quarter inspiration and three-quarters perspiration - not just his own.
Obama's greatest natural advantages over his two opponents - given their ages and decades of public service - were his outsider sensibility and promise of generational renewal.
As someone from humble means and only recently wealthy, he has been plugged into an understanding of the public mood in a way they haven't. Can that quality survive behind the white walls of 1600 Pennsylvania Avenue?
In the dying days of the campaign, some prominent pundits backing McCain were reduced to arguing that the haphazard campaigner was a mirage and that the real, historic figure would re-emerge as President.
On the other hand, the public will hope that with Obama, the campaigner they saw was the real deal.
Obama is highly unusual in that he exists in the public consciousness as both a pragmatic politician and as a symbolic, historic figure - because of his achievement in becoming the first African American President of the United States.
Probably the nearest modern equivalent is former South African President Nelson Mandela who was a leader in both a political and moral sense.
America has given the world a great and generous moment. In the land of the modern Caesars, they have passed over the son and grandson of admirals in favour of the son of a Kenyan student with Hussein as a middle name.
But symbolism aside, Obama's superbly-run campaign showed he was the right man for the job.
* He defeated - and subsequently deployed - the champions of his party, the Clintons.
* He made the previously smoothly purring Republican election machine look like a banged-up old Cortina.
* During the financial crisis, his looked like the steady hand that needed to be locked on the tiller.
* He used the three debates to convince the public that he was capable, knowledgeable and worth a chance.
* He hitched his movement to the internet to an extent that had never been seen before, for fundraising and mobilising.
* He got his basic organisation, strategy, tactics and campaign talent right.
* He is surrounded by talented economic and foreign policy advisers with recent experience of government.
With his limited resume and nice line in rhetoric, Obama was early on in the primary campaign often dismissed as an "empty suit".
But he got the strategy right for the battlefield and stuck to his message. In a time of deep disgruntlement with the Republicans, President Bush and the Iraq war, this was destined to be a "change" election.
Clinton, the party establishment favourite, relied on an enviable list of donors who gave the maximum US$2300 ($3800) allowed.
But Obama spread his net wide, building a bank of small individual donors via the internet who gave small amounts and could be regularly tapped for more.
By September 3.2 million people had contributed to his campaign and he was on-course to raise more than Bush and John Kerry combined in 2004.
As Clinton concentrated on winning big primaries, Obama accumulated caucuses and Republican states.
Obama's organisation created thousands of field offices across the country. The Washington Post reported there were 10,000 Obama volunteers in Virginia alone.
With money pouring in, he was able to compete aggressively in Republican-held states during the general campaign, blanketing them with ads as his ground operation launched voter registration drives.
After the primary season, Obama was able to re-stock his shelves with experienced Clinton Administration staffers, which put some centrist meat on the bones of his operation - essential to appealing to moderate voters.
There were mistakes:
* The campaign appeared to be naive or sloppy early on about the potential problems of the Rev Wright, the Weather Underground and Tony Rezko.
* A couple of Obama's advisers slipped up with inadvisable comments over Nafta in Canada and private views of Clinton.
* There was an awkward moment in a debate when Obama told Clinton "you're likeable enough".
* There was the damaging statement about "bitter" people "clinging" to God and guns.
* And the more recent difficulty over "spreading the wealth around".
Some of his statements - "together we will change the world!" - meant to fan the aspirational link with his Obamarmy, can seem bombastic to a sceptical ear.
Obama over-reached several times, with his victory rally before the Victory Column, his classical convention columns, his short-lived presidential-style seal. Such moves fed a McCain campaign narrative that Obama was being presumptive but they probably reflected an anxiety to appear presidential when the candidate was trying everything to prove himself.
It wasn't until the financial crisis that the presidential suit finally seemed to fit Obama's shoulders. Obama now has both a definable reason for "change" and - with his plans for a Green New Deal driving the jobs of the future - a pathway ahead.
It took Obama a long time to find his best voice, where rhetoric entwined with details in a focused delivery. But it came together in his convention speech and during his debates with McCain.
But how does Obama deal with raising hopes to a peak of Mt Everest proportions and yet avoid an avalanche of disappointment?
He is helped, in a way, by the sheer size and historic nature of the problems that have to be confronted. It's not unlike the forbidding mood in the aftermath of September 11 - there's both trepidation and the glint of an opportunity for a new direction.
He will need to maintain the unusual Democratic discipline of the past six weeks and widen his embrace to include Republicans - as he has said he intends to do - so as not to squander the moment.
That will be difficult with the Democrats flexing their muscle as the Republicans conduct an internal inquisition.
But a Democratic-dominated Congress also gives Obama a good chance to push through his agenda.
Obama will again be helped by having to deal with the market meltdown. There's the world summit straight ahead, plans for a financial stimulus package, and the need to have administration officials in place quickly. It means he will hit the ground running.
His politically revolutionary campaign suggests that there's at least a chance Obama could have success longer term at providing leadership for an evironmental technology boom.
A remarkable aspect of the campaign was the amount of self-organising that occurred. Motivated volunteers would download materials from the campaign, get in touch with like-minded others through social networking and conduct registration drives without direction from higher up.
Obama will be hoping he can set the policy framework and provide the inspiration to unleash potential.
Maybe having a one-time community organiser in the White House is the right way of bringing out America's 21st century promise.
