Obama's speech at the Democratic National Convention wrapped up at about 10 p.m. Thursday.
A capacity crowd of 80,000 people filled a football stadium in Denver.
Call it an improbable journey from a campaign that began modestly on the capitol steps of the old capitol building in Illinois, to Invesco Field, packed with people. Obama took his message to America. It was a message he packed with passion, attacks and promises as to what he would do if he gets the top job in the land.
Sen. Dick Durbin, (D) Illinois, introduced Obama, saying, "America can turn the page and welcome a new generation of leadership. Yes, America can. Yes, we can."
Obama started with the personal.
"Four years ago, I stood before you and told you my story," Obama said.
He turned to the political.
"We are a better country than this," he said.
He tied the sagging economy, home foreclosures and unemployment to the Bush administration.
"These challenges are not all of government's making. But the failure to respond is a direct result of a broken politics in Washington and the failed presidency of George W. Bush," Obama said.
He commended Republican John McCain's military service but blasted his opponent's stands.
"But the record's clear: John McCain has voted with George Bush 90 percent of the time," Obama said.
He railed McCain's view of what comprises economic success.
"We measure the strength of our economy not by the number of billionaires we have or the profits of the Fortune 500, but by whether someone with a good idea can take a risk and start a business, or whether the waitress who lives on tips can take a day off to look after a sick kid without losing her job," Obama said.
Obama laid out a series of presidential promises.
"I will cut taxes, cut taxes, for 95 percent of all working families," he said. "In ten years, we will finally end our dependence on oil from the Middle East."
And he defended himself against those who might say that he won't be strong enough in managing America's foreign policy interests and its military.
"We are the party of Roosevelt. We are the party of Kennedy. So don't tell me that Democrats won't defend this country. Don't tell me that Democrats won't keep us safe," he said. "I will end this war in Iraq responsibly, and finish the fight against al Qaeda and the Taliban in Afghanistan."
This was his night to create an impression on voters that he hopes will last to Election Day.
"We must march into the future," he said in closing.
Illinois delegation reacts
Among the thousands there Thursday night, there was one group in particular that relished the moment. They've known Obama since his days in the state senate, since the first time he wowed the Democrats at the DNC four years ago. It's the Illinois delegation.
Dozens of Illinois politicians, officials and regular people have known Obama for at least a decade. Whether or not they saw the promise, they have all uniformly been watching in awe for the last few months as he climbed a seemingly unscaleable political mountain to defeat much better known politicians, including Sen. Hillary Clinton.
The Illinois delegation was filled with old friends and former colleagues of Obama's, bursting with pride and joy as one of their own took the stage in the center of Invesco Field to make history by claiming the Democratic nomination on the 45th anniversary of Dr. Martin Luther King's "I Have a Dream" speech and laying out his case for the bulk of Americans who don't know him well, trust him yet or see him as commander-in-chief in a time of war, terrorism and economic turmoil.
"I'm just ready for change, eight more years. He's dealing with grassroots people who are going to be out, knocking on doors, getting the vote out. I think it's awesome," said Joyne Thomas, Flint, Mich.
"He covers a lot, a lot of the things that are important to me and obviously important to everybody here, anywhere from taking care of the vets, to taking care of the kids, it's all important. And it's all something that needs to be taken care of. It's time for a change, this is great," said Steve Spinosa, Denver, Colo.
The celebration began early as the Illinois delegation gathered in the stadium even before the sun went down. As they waited for the substance of Obama's speech, they reveled in a moment of history, a moment in time perhaps unlike any they've seen before.
"I think today everybody is celebrating. Tomorrow we roll up our sleeves and get to work to get him elected," said State Sen. Iris Martinez, (D) Chicago.
"Once in a lifetime can one experience this kind of thing, and this man laid it out. I am looking forward to November 4 so we can come out and make it official that he is president of the United States," said State Rep. Connie Howard , (D) Chicago.
"One of the delegation's senior statesman said it was a unique event in American political history.
"There's so much enthusiasm and excitement because he turned on a whole new generation of voters," said Abner Mikva, former north suburban Congressman.
But there's also a group of voters out there, predominantly white, working class, older Americans, who have a lot of doubts about Obama. They heard the lofty and eloquent and moving rhetoric. They've maybe read the books. They've seen his style, but they wondered if he cared enough about them, if he knew enough about the issues that are important to him. He tried to make the sale in the most persuasive of ways, and now the question is whether the American public is buying.
For now, this Democratic convention is coming to a close, and its nominee is now on a historic quest. His challenge is to convince the voters outside this football stadium and for that matter, those who are outside the traditional Democratic Party. But in the Super Bowl of American politics, the kickoff has occurred and Obama is the first on the board.
Chicagoans back home react
Back in Chicago, Obama supporters marked this historic night by hosting parties, including one at Obama's volunteer headquarters in the West Loop.
There was also a big bash at the Regal Theater.
People throughout the Chicago area watched Obama's speech. They gathered in different places, bars, restaurants, barbershops, living rooms and even theaters. At the Regal Theater, more than 600 people watched. It was an emotional time for them - part revival, part pep rally. Chicagoans witnessed history filled with pride and emotion.
"Many of us never thought this day would come. Yes, we can," said Beatrice Sumlin, Chicago resident.
The Regal Theater on the city's South Side opened its doors for Obama supporters. Dozens shared the moment, and his words moved them.
"It's a feeling of change in America, complete change, not for the elite, but the middle class, change that will affect the world," said Adam Lash, Aurora resident.
"The thing is, if we believe and stick to the values and do what's right, right will win out," said Thomas Ellis, Chicago resident.
"He came out so eloquently. He had the smile in his eye and he had that love. It just got everybody in the room excited," said Harold Dennis, Obama supporter.
From large venues to small ones, thousands gathered in living rooms across the Chicago area.
"It speaks to what we as normal Americans, as middle class Americans, as even lower-middle class Americans, feel," said Savannah Williams, Obama supporter.
Obama's political rise has inspired some to take action on the grassroots level, opening up their homes for the evening.
"You're meeting your neighbors, and you're inviting them into your home. It's not just, 'Oh I recognize you.' It's like, 'Come over!'" said Ashley Ahlborn, house party hostess.
Also gathering were Republicans and Democrats who support Senator John McCain.
"We're just here to find out what Barack Obama is going to be, what his campaign is going to be about, what he's going to be about, and also what McCain is up against," said Diana Maxwell, McCain supporter.
"In a time when money is precious for everybody, I wanted to see what the $5 million they spent on this night actually bought. So far, I'm not that impressed," said Kevin DuJan, Democrats for McCain.
On Firday, presumptive Republican presidential nominee McCain is expected to announce his choice for a running mate.
Prospects include Minnesota Governor Tim Pawlenty, Senator Joe Lieberman of Connecticut, former Massachusetts Governor Mitt Romney and former Pennsylvania Governor Tom Ridge.
McCain and his wife Cindy left Phoenix Thursday and headed for Ohio. That's where he and his vice presidential pick were scheduled to appear at a rally Friday.
But in a campaign ad, McCain said Thursday was all about Obama.
"Senator Obama, this is truly a good day for America. How perfect that your nomination would come on this historic day. Tomorrow we'll be back at it. but tonight, senator, job well done," McCain said in the ad.
The Republican National Convention begins in St. Paul, Minnesota, Monday. Preparations were underway at the Xcel Energy Center, which is the home of the Minnesota Wild hockey team.
Fixing Washington"America, now is not the time for small plans," the 47-year-old Illinois senator told an estimated 84,000 people packed into Invesco Field, a huge football stadium at the base of the Rocky Mountains. Polls indicate a close race between Obama and McCain, the Arizona senator who stands between him and a place in history. On a night 45 years after Martin Luther King Jr. delivered his "I have a Dream Speech," Obama made no overt mention of his own race. "I realize that I am not the likeliest candidate for this office. I don't fit the typical pedigree" of a presidential candidate was as close as he came to the long-smoldering issue that may well determine the outcome of the election. Campaigning as an advocate of a new kind of politics, he suggested at least some common ground was possible on abortion, gun control, immigration and gay marriage. Obama delivered his 44-minute nominating acceptance speech in an unrivaled convention setting, before a crowd of unrivaled size -- the filled stadium, the camera flashes in the night, the made-for-television backdrop that suggested the White House, and the thousands of convention delegates seated around the podium in an enormous semicircle. Obama and his running mate, Sen. Joseph Biden. of Delaware, leave their convention city on Friday for Pennsylvania, first stop on an eight-week sprint to Election Day. McCain countered with a bold move of his own, hoping to steal some of the political spotlight by spreading word that he had settled on a vice presidential running mate. Minnesota Gov. Tim Pawlenty canceled all scheduled appearances for the next two days, stoking speculation that he was the one. Rep. John Lewis of Georgia spoke first of the anniversary of King's memorable speech. "Tonight we are gathered here in this magnificent stadium in Denver because we still have a dream," said the Georgia lawmaker, who marched with King, supported Obama's primary rival, Hillary Rodham Clinton, then switched under pressure from younger black leaders in his home state and elsewhere. Obama's aides were interested in a different historical parallel from King -- Obama was the first to deliver an outdoor convention acceptance speech since John F. Kennedy did so at the Los Angeles Coliseum in 1960. The speech didn't mention it, but Obama has called for raising taxes on upper-income Americans to help pay for expanded health care and other domestic programs. He did not say precisely what he meant by breaking the country's dependence on Mideast oil, only that Washington has been talking about doing it for 30 years "and John McCain has been there for 26 of them." His pledge to end the war in Iraq responsibly was straight from his daily campaign speeches. "I will rebuild our military to meet future conflicts. But I will also renew the tough, direct diplomacy that can prevent Iran from obtaining nuclear weapons," he added. As he does so often while campaigning, Obama also paid tribute to McCain's heroism -- the 72-year-old Arizona senator was a prisoner of war in Vietnam -- then assailed him. "Sen. McCain likes to talk about judgment, but really, what does it say about your judgment when you think George Bush was right more than 90 percent of the time? Former Vice President Al Gore picked up on the same theme. "If you like the Bush-Cheney approach, John McCain's your man. If you want change, then vote for Barack Obama and Joe Biden," he declared. The much-discussed stage built for the program was evocative of the West Wing at the White House, with 24 American flags serving as a backdrop. A blue carpeted runway jutted out toward the infield, and convention delegates ringed the podium. Thousands more sat in stands around the rim of the field. The wrap-up to the party convention blended old-fashioned speechmaking, Hollywood-quality stagecraft and innovative, Internet age politics. The list of entertainers ran to Sheryl Crow, Stevie Wonder and will.i.am, whose Web video built around Obama's "Yes, we can" rallying cry quickly went viral during last winter's primaries. In a novel bid to extend the convention's reach, Obama's campaign decided to turn tens of thousands of partisans in the stands into instant political organizers. They were encouraged to use their cell phones to send text messages to friends as well as to call thousands of unregistered voters from lists developed by the campaign. In all, Obama's high command said it had identified 55 million unregistered voters across the country, about 8.1 million of them black, about 8 million Hispanic and 7.5 million between the ages of 18 and 24. Those are key target groups for Obama as he bids to break into the all-white line of U.S. presidents and at the same time restore Democrats to the White House for the first time in eight years. The Democratic man of the hour paid a brief visit to members of his home-state Illinois delegation before the curtain went up on his show. "I came by (because) I had this speech tonight. I wanted to practice it out on you guys. See if it worked on a friendly audience," he joked. Obama's hopes of victory rely on holding onto the large Democratic base states such as California, New York, Michigan and his own Illinois, while eating into territory that voted for George W. Bush. Ohio tops that list, and Democrats have also targeted Montana, North Dakota, Virginia and New Mexico, among others, as they try to expand their Electoral College map. Biden was brutally frank about the Democrats' chances in an appearance before one state's delegation. "This is not hyperbole: We cannot win without Pennsylvania," he said. Polling shows the race for that state's 21 electoral votes close. Both the two previous Democratic candidates, Gore and John Kerry carried Pennsylvania over Bush. Biden, who was born in Scranton, Pa., and represents a state that shares a border with Pennsylvania, is expected to spend large amounts of time campaigning in the state over the next several weeks.
The Associated Press contributed to this report.