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Candidates travel to key locations on Election Day

After over a year of campaigning and debating, and $984 million invested in presidential campaign advertising, Americans went to polling places across the nation Tuesday to render their verdict on President Barack Obama and Republican presidential candidate Mitt Romney.

Mitt Romney visits Pennsylvania and Ohio before heading to Boston to wait for results. NBC's Jay Gray reports.

Showing the intensity of the race, which polls show as extremely close, Romney and his running mate Rep. Paul Ryan of Wisconsin made last-minute Election Day appearances in two of the most hotly contested battlegrounds: Ohio and Pennsylvania. Ryan arrived midafternoon in Richmond, Va., for his last 2012 campaign appearance.

Romney told supporters at a call center outside Pittsburgh that they "don't need to be disparaging of the other guy. The president has run a strong campaign, I believe he is a good man and wish him well, and his family well. He is a good father and has been a good example of a good father, but it is time for a new direction. It is a time for a better tomorrow."

Governor Romney plans to hit two more states on Election Day after squeezing in five events in four battleground states on the eve of the vote. NBC's Peter Alexander reports.

Vice President Joe Biden also touched down in Cleveland to make an Election Day visit and to thank campaign volunteers. At one point, the Romney, Ryan and Biden planes were all simultaneously parked on the tarmac in Cleveland – a final symbolic expression of the importance of the state’s 18 electoral votes in the race to get to 270.

Aboard Romney’s chartered plane, his chief strategist Stuart Stevens reacted to Biden’s Ohio stop by musing about Democrats who claimed the GOP ticket was displaying "panic” by campaigning today.

NBC's Chuck Todd offers a guide of what to watch on election night as the polls close and reveals what possible scenarios could play out in the Electoral College.

Early Tuesday morning, the Obama campaign sent out a text message urging supporters to pick up the phone to woo another voter for the president: “Will you make one call for President Obama? Reply CALL and we'll send you the name & phone number of one voter in a key state who needs to hear from you.”

At their stop at a Wendy’s in Cleveland, Romney ordered a quarter-pounder with no cheese along with chili and a baked potato, while Ryan replied to a reporter’s question about how he felt by saying: "I'm running on fumes."

Obama took time out from the frenzied last-minute campaigning and vote forecasting to play a pickup basketball game with friends and staffers at a court in Chicago.

Justin Sullivan / Getty Images

Republican presidential candidate, former Massachusetts Gov. Mitt Romney (R) and his running mate Rep. Paul Ryan (R-WI) smile while greeting workers at a GOP Victory Center in Richmond Heights, Ohio, on November 6.

The president was also scheduled to do interviews with radio stations in media markets in most of the battleground states: in Des Moines and Cedar Rapids, Iowa; Milwaukee, Wis.; Denver, Colo.; Cleveland and Cincinnati, Ohio; Las Vegas, Nev.; Miami and Tampa, Fla., and – reaching voters in the vital northern Virginia suburbs, a station in Washington, D.C. In 2008, Obama carried all seven of the states in which his radio interviews were airing on Tuesday.

Romney also turned to Election Day radio interviews to make one last appeal to voters, with appearances on stations in Ohio, Washington, D.C. and Richmond, Va.

In a morning drive-time interview with Jimmy Barrett on WRVA in Richmond, Romney said, “We’re bouncing around a bit – just going to polls and saying ‘hi’ to people and making sure we leave nothing in the locker room. We’re putting it all out there on the field.”

Mitt Romney, Paul Ryan and Joe Biden vote on Election Day, along with thousands of Americans. NBC's Leanne Gregg reports.

He added, “I can’t imagine an election being won or lost by let’s say a few hundred votes, and you spent your day sitting around. I mean, you’d say to yourself, ‘Holy Cow, why didn’t I keep working?”

Whether voter turnout  -- especially Democratic turnout -- matches that of 2008, when Obama was swept into the White House with a popular vote plurality of more than 9.5 million votes, will be crucial to Tuesday’s outcome

In Ohio, Secretary of State Jon Husted reported that nearly 1.8 million absentee ballots had been cast, surpassing the 2008 presidential election figure.

And in Florida Tuesday morning, Secretary of State Ken Detzner predicted a record turnout, saying as many as 9 million people overall could vote in his state. Nearly 8.4 million people voted in Florida in 2008.

Detzner said he was not concerned that the long lines during the eight-day early vote period would dampen enthusiasm Tuesday.

In another key state, Colorado, as of Monday night, more than 1.7 million voters had cast early ballots. In 2008, 2.4 million voted in the state.

At stake Tuesday was not only the presidency but control of the Senate and the House of Representatives. If Romney wins and Republicans can score a net gain of only three seats in the Senate they would become the majority party and control the agenda. If Obama wins the Republicans would need a net gain of four seats to win the Senate. The GOP is expected to retain control of the House.

NBC News’s Carrie Dann, Garrett Haake, and James Novogrod contributed to this story.