Given a historic chance to go it alone as an independent nation, Scottish voters chose to stick with the United Kingdom following a campaign that was marked by extraordinary turnout and profound division.

Final results showed Friday that the “no” side won an overwhelming advantage, with a 55 percent majority compared to 45 percent for the “yes” camp. Unionist leaders proclaimed that Scotland had clearly voted to remain part of the United Kingdom. Supporters erupted in raucous celebration.

A “no” vote breathes new life into a 307-year union that had appeared in grave danger of breaking apart. The unionist victory was quickly heralded by relieved British officials who had come perilously close to having to preside over a messy and humiliating divorce.

“It would have broken my heart to see our United Kingdom come to an end," British Prime Minister David Cameron said in a statement in front of 10 Downing Street.

Instead, Britain was set to remain whole for the foreseeable future, and “yes” voters’ dream of an independent Scotland could be dead for a generation or more, he said.

“I am delighted,” Cameron said. “Now is the time for our United Kingdom to come together and move forward.” He called the vote a “clear result.”

Throughout the debate, the “yes” camp was consistently louder, more visible and seemingly better organized. But unionists insisted all along that they represented “a silent majority” of Scots — a prediction that was borne out in the vote totals.

“The silent have spoken," Alistair Darling, leader of the unionist Better Together campaign, told cheering backers in Glasgow. He said the ties that bind the United Kingdom should “never be broken.”

In a speech in Edinburgh, independence leader Alex Salmond conceded defeat and urged his followers to respect the result. Later Friday, he announced his resignation.

“I accept the verdict of the people, and I call on all of Scotland to follow suit in accepting the democratic verdict,” he said.

But he also proclaimed the Scottish independence movement a force to be reckoned with in U.K. politics. And he made clear he will hold British leaders accountable for pledges they made in the final days of the campaign to quickly devolve power away from London and toward the Scottish capital.

“I don’t think that will ever be allowed to go back to business as usual,” he said.

Cameron on Friday morning reaffirmed his pledge of devolved power for Scotland, and expanded it to Wales, Northern Ireland and England, saying the Scottish vote represents “an opportunity to change the way the British people are governed.”

Wales, Scotland and Northern Ireland already have their own parliaments or assemblies. England does not, and Cameron did not spell out exactly how he intends to give English voters more direct control over their own affairs.

The announcement of results came just hours after nearly all of Scotland turned out to vote on Thursday in a referendum marked by civility and passion. The vote offered residents of this ancient land the chance to create the world’s newest independent nation by breaking up one of its oldest unions.

From remote and pastoral islands to the gritty, post-industrial streets of Glasgow, Scots had lined up in the early morning mist on Thursday, and they kept coming through the day and well into the night.

The campaign deeply divided Scots, with pre-election polls showing voters almost evenly split. After two years of virtually nonstop debate and discussion, tempers flared in the final weeks, and both sides charged the other with intimidation.

But on the whole, the referendum debate was remarkable for the seriousness with which voters weighed such a stark choice, and the peaceful manner in which they expressed it on Thursday.

“The people of Scotland don’t realize how lucky they are,” said a teary-eyed Bernie MacKin, 45, who spoke over the shrill notes of a bagpipe at a “yes” rally in Glasgow Thursday night. “Other countries have had to fight for their freedom, but we just have to put an X in a box.”

All through Thursday, Scots calmly and resolutely did just that, while flag-waving activists sped through towns and cities, knocking on doors and offering rides in a frantic push to maximize turnout. Turnout across Scotland was hovering just above an astounding 85 percent.

“There’s just been an explosion in political engagement,” said John MacDonald, director of the Scottish Global Forum. “And by and large, people have been incredibly well-behaved.”

Now, Scotland will be under pressure to quickly heal its divisions. Inevitably, Friday’s result will leave nearly half the population deeply disappointed.

Independence advocates had been pushing for Scotland to break from the United Kingdom for decades. Salmond said repeatedly in the debate’s final days that he would not advocate for a new referendum if “yes” lost, even if the vote was close.

A “yes” win would have forced unionists to grapple with the idea of losing a national identity.

“I’m very proud to be Scottish. I’m also very proud to be British,” said Angus Bruce, a 73-year-old retired whiskey salesman.

If he could no longer be both in Scotland, Bruce said on Thursday before the results were in, he and his wife would consider moving to England.

Indeed, the vote carried vast implications not only for Bruce and the 5.3 million people of Scotland, but also the 59 million people in the rest of the United Kingdom who would have been left behind if Scotland had chosen to break away.

A “yes” outcome Thursday would have set Scotland on a course for independence by 2016, and would have precipitated intricate and difficult negotiations between British and Scottish authorities over the terms of divorce.

North Sea oil revenues, Britain’s nuclear weapons program and the use of the pound sterling would have all been on the line, along with dozens of other questions as the two sides divided this island along a border that has hardly functioned like one since 1707.

The victory for “no” will be far less jarring, but it brings its own set of complications.

As polls tightened in the final weeks before the vote, the leaders of Britain’s three main parties — including Cameron — tried to entice wavering Scots by promising them greater autonomy if they chose to stick with the union.

But the leaders disagree over the details, and the promises have spawned a backlash among some in England who worry that Scotland is being given a sweetheart deal at their expense.

Britain’s leaders — who have been an object of scorn throughout the campaign — will now be under pressure to deliver on their promise of devolved powers and prove they have heard the message from voters who see London as out of touch.

“This has all been about getting closer to the government you elect,” MacDonald said. “For 99 percent of ‘yes’ voters, that’s what they were looking for.”

Scotland already has its own parliament, with responsibility for managing the nation’s health care, education and legal systems. But Scottish independence leaders — who came to power in Edinburgh on a platform of giving the nation an up-or-down vote on independence — have argued that Scotland’s people need complete control over their own affairs.

Nationalists said an independent Scotland, unshackled from London’s austerity-minded Conservative-led government, would have been modeled on Scandinavian countries that spread their wealth broadly and offer their citizens a generous package of government support.

Unionists sought to portray the nationalist agenda as a fantasy.

Many independent economists have agreed, questioning whether Scotland can build the sort of egalitarian society that its leaders envision, especially with declining oil revenues and uncertainty hovering over the newly independent nation’s currency.

The “no” side’s warnings of economic doom spurred a backlash among Scots, however, and prompted the pro-union camp to recalibrate its message. In the final days, unionists emphasized their love for Scotland — not their prophecies of failure. Polls suggested the shift may have helped halt growing momentum for independence.

Scotland’s vote Thursday was closely watched around the world, not least in Washington, which has looked on anxiously — but mostly silently — as its closest and most reliable ally faced partition.

While U.S. officials initially said they would stay completely out of the referendum debate — arguing that independence was a matter for the Scots, not for outsiders — tightening polls led President Obama to gently intervene.

Over the summer he expressed support for keeping the United Kingdom together, and he reiterated that stance late Wednesday, on Twitter. “I hope it remains strong, robust and united,” read the tweet, which was signed “bo.”

Adam reported from Glasgow. Daniela Deane contributed to this report from Rome.