DEVELOPING ...

President Obama will win re-election, Fox News projects. The call comes after the president was the projected winner in the crucial battleground of Ohio, and subsequently won both Iowa and Oregon. This put Obama over the required 270 electoral votes.

ORIGINAL STORY ...

Mitt Romney claimed his first battleground prize of the night with a projected victory in North Carolina, answering an early string of swing-state victories Tuesday by President Obama.

Fox News projects Romney will win the state, worth 15 electoral votes, where the Democrats held their 2012 convention.

Obama, though, has taken the lead in the electoral-vote count. The president earlier scored a big win in Pennsylvania, a vital battleground where Romney made a late play for support. Obama also walked away with a win in the swing states of New Hampshire, Wisconsin and Michigan, Fox News projects.

The rest of the big swing states where polls have closed -- Nevada, Iowa, Colorado, Florida, Ohio and Virginia -- were all too close to call.

Elsewhere, Obama and Romney each racked up expected victories Tuesday night in relatively safe territory.

Romney is the projected winner in Utah, Montana, Arizona, Missouri, Idaho, Texas, Louisiana, Kansas, North Dakota, South Dakota, Nebraska, Wyoming, Alabama, Mississippi, Oklahoma, Tennessee, Arkansas, West Virginia, South Carolina, Georgia, Indiana and Kentucky.

Fox News projects Obama is the winner in his home state of Illinois, California, Hawaii, Washington, Minnesota, New Mexico, Maine, New York, Delaware, Connecticut, Maryland, Massachusetts, New Jersey, Rhode Island, Vermont and the District of Columbia.

The latest batch of poll closings and calls put Obama in the lead. Obama has 244 electoral votes to Romney's 203; it takes 270 to win. But with a number of states still not called, the lead could continue to swing back and forth throughout the night.

Ohio, where polls closed at 7:30 p.m. ET, is too close to call. Fox News exit polls show Romney and Obama running neck-and-neck in the Buckeye State. The contest is considered critical -- only twice in U.S. history has anyone won the presidency without winning Ohio.

In Virginia, Fox News exit polls show the race so tight that neither Romney nor Obama have even a slight lead. Officials in the state also made a late decision to allow voters in line at the closing time of 7 p.m. ET to still cast ballots, slowing the release of results.

The razor-thin margin between the candidates means the campaigns could be in for a long night, after the candidates wound down their campaigns earlier in the day.

At Obama headquarters in Chicago, aides were optimistic, with two advisers telling Fox News they are outperforming their turnout models in Florida, Ohio and Virginia.

Romney advisers note they can still get to 270 if the Republican carries those three states, plus either Iowa or Colorado.

Election Day was unexpectedly busy for the campaigns. While Obama himself kept a low profile in Chicago, the campaign dispatched Vice President Biden to Ohio where he visited a Cleveland restaurant and later posed for pictures with volunteers before joining up with the president.

Romney, meanwhile, made stops in Ohio and Pennsylvania -- two key swing states -- before heading back to campaign headquarters in Boston.

"This is a big day for big change," Romney told a crowd of campaign volunteers outside Cleveland.

The visits rounded out a grueling battle for the White House. For Obama, the election is the last time he says his name will appear on a ballot. For Romney, the vote marks the close of a nearly six-year run for the presidency.

In an airtight contest, both candidates were expressing confidence as millions of voters flocked to the polls. Obama visited a Chicago campaign field office Tuesday morning, before playing his traditional Election Day game of pick-up basketball.

"The great thing about these campaigns is, after all the TV ads and all the fundraising and all the debates and all the electioneering, it comes down to this," Obama said.

Take your best shot at predicting the final electoral map for the 2012 presidential election

Voting kicked off overnight in two tiny villages in northern New Hampshire. Obama and Romney each won five votes in the small town of Dixville Notch, which was the first to announce its results after polls opened and closed within 43 seconds.

In Hart's Location, N.H., Obama won with 23 votes, Romney received 9 and Libertarian Gary Johnson received 1 vote after 5 minutes, 42 seconds of voting. The towns have enjoyed first-vote status since 1948.

Obama closed out his campaign with a late-night rally in Iowa on Monday. The event was held in the same state where his 2008 caucus victory jump-started his path to the White House.

The president was photographed with tears running down his face as he spoke before a crowd of 20,000 supporters, telling them "this is where our movement for change began."

The president never mentioned Romney in his closing appeal, which sought to draw on the hope and optimism of his first campaign.

Romney returned Monday night to New Hampshire, where he launched his bid, telling supporters during his final campaign rally that he needs their votes again.

"It's all your votes and your work right here in New Hampshire that will help me become the next president of the United States," Romney told a thunderous capacity crowd at the Verizon Wireless Arena, which holds about 10,000 people. "We thank you and we ask you to stay in it all the way to the victory tomorrow night."

The final hours of the exhausting 2012 contest were played out at earlier mega-rallies across a half-dozen states. Each candidate sought to close the deal with voters promising "change," while accusing the other of peddling an agenda that would choke the country's already meager economic recovery.

Ohio is arguably the hardest-fought contest of the race, with both candidates visiting Monday and both pouring millions into that battleground. But with polls giving Obama a slight edge in the Buckeye State, Romney's campaign also has made a late play for Pennsylvania -- a win in Pennsylvania could allow the Republican nominee to lose Ohio and still have a pathway to the 270 electoral votes it takes to win.

The Obama campaign, though, dismissed Romney's Election Day efforts as a "Hail Mary."

Which states have Obama and Romney visited the most? Check our Candidate Tracker to find out

Voters across the country on Tuesday were casting ballots not just in the presidential race, but a host of congressional races that will determine the balance of power on Capitol Hill next year. Democrats currently control the Senate by a narrow 53-47 margin.

It's still an uphill climb for Republicans to take control -- they have a much easier shot at retaining control of the House.

Meanwhile, voters are deciding on an array of controversial measures at the state level, including several that would partially legalize marijuana.

In the presidential race, battleground polls show a mixed picture. While Obama has the edge in Ohio, for example, Romney has the edge in the crucial state of Florida. Nationally, the latest and final Gallup survey showed Romney with 49 percent and Obama with 48 percent support.

By most estimates, Obama comes into Election Day with a slight advantage in the electoral vote count. The RealClearPolitics electoral map shows the states likely to vote for Obama are worth 201 electoral votes, while those likely to vote for Romney are worth 191. It takes 270 to win.

The toss-ups include: Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin.