A day ahead of the vote, U.S. President Barack Obama and his Republican Party challenger Mitt Romney are locked in a tight race, with polls showing Obama ahead slightly in several swing states that will decide who claims the White House.
Ohio, and its 18 electoral votes, are seen by analysts as a possible key to election success for the candidates.
Both Obama and Romney campaigned in the Midwest state on November 4. Romney told voters in Ohio that Obama had achieved little during his first term as president, and didn't deserve another.
"I'd ask them to put aside all the speeches, all the ads and all the attacks and to look at the record because you see talk is cheap, but, a record is real and it's earned with real effort," Romney said.
"Change is not measured in words and speeches, change is measured in achievement, so let's look at that record."
On another stop in the northeastern state of New Hampshire, Obama said he would work hard to bring about real change.
"You know where I stand, you know what I believe. You know I tell the truth and you know I will fight for you and your families every single day as hard as I know how, as long as I have the privilege to be your president," Obama said.
"So when you ask yourself the question who's going to fight for me and bring about real change you know that I know what real change looks like because I fought for it alongside you. I've got the scars to prove it. I've got the gray hair to show for it."
According to the Center for Responsive Politics, about $2.6 billion will be spent on the 2012 presidential election, a decrease from the $2.8 billion spent in 2008.
With reporting by Reuters and AP