On Monday, candidates Obama and McCain traveled through key states  before they go to the polls hours later on Tuesday.

"I only have one word for you: tomorrow," Democrat Obama said at his final rally.

"After decades of broken politics, eight years of failed policies, 21 months of campaigning, we are less than one day away from bringing change," he said.

The final major rally in Manassas, Virginia, on Monday night, marked the 20th time his campaign has stumped in Virginia.

His running mate Joe Biden will also visit the state Tuesday when the polls open and Obama will return to Chicago around 1 a.m.

McCain campaigned until 2 a.m. Tuesay with his final stop in Prescott, Arizona.

The Republican had a rally on the steps of the courthouse, where his hero Barry Goldwater launched his 1964 presidential bid. The site is also where McCain always makes his final stop in his Senate campaigns.

Earlier Monday, McCain called on Pennsylvania to help him erase his deficit in the polls and score an upset over Obama.

Republican presidential candidate Sen. John McCain, R-Ariz., left, accompanied by his wife Cindy, gestures as they arrive for a rally in a hanger at Pittsburgh International Airport in Moon Township, Pa., Monday, November 3, 2008. [Agencies]

"Just one day left until we take America in a new direction. We need to win in Pennsylvania and tomorrow, with your help, we will win," McCain said, pounding his fist on the podium at an event in Moon Township.

"Volunteer, knock on doors, get your neighbors to the polls. I need your vote," he said.

Obama leads McCain by 8 percentage points in Pennsylvania, 51 percent to 43 percent, according to CNN's latest average of state polls.

National polls show Obama leading McCain by about 7 percentage points.

As they sprint toward the finish line, the candidates and their running mates were visiting more than a dozen states Monday.

They were using their final stops to urge supporters to volunteer and help get out the vote.

"If in these final hours, you will knock on some doors with me, make some calls with me, go to vote.

"If you'll stand with me and fight with me, I promise you: We will not just win Florida, we'll win this election," Obama said at a rally in Jacksonville, Florida.

US Democratic presidential nominee Senator Barack Obama greets a supporter during a rally in Jacksonville, Florida, November 3, 2008. [Agencies]

Earlier Monday, McCain addressed a much smaller crowd in the same state.