(CNN) -- Sens. Barack Obama and John McCain worked into the early morning in their last efforts to sway voters before they go to the polls hours later on Tuesday.
"I only have one word for you: tomorrow," 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."
The final major rally in Manassas, Virginia, on Monday night, marked the 20th time his campaign has worked a crowd in Virginia.
Sen. Joe Biden will also visit the state Tuesday when the polls open. Obama's plane landed in Chicago after 1 a.m. ET Tuesday. He made no more campaign stops, however, ending a difficult day that began with news of his grandmother's death.
McCain campaigned until nearly 3 a.m. ET, concluding in Prescott, Arizona.
McCain rallied 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, Sen. John McCain called on Pennsylvania to help him erase his deficit in the polls and score an upset over Sen. Barack Obama.
"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. Watch Obama's last rally, in Virginia »
McCain's campaign has said it is buoyed by its internal numbers not showing up in public polling.
In the past two presidential elections, pre-election polling in Pennsylvania showed strong support for Democrats Al Gore and John Kerry, but both candidates ended up carrying the state by narrow margins.
McCain and his running mate, Alaska Gov. Sarah Palin, have visited Pennsylvania 10 times in 15 days. The state has 21 electoral votes.
In his last visit to the state before voters go to the polls, McCain said, "The pundits have written me off just like they've done four or five times in the past. ... They may not know it, but the Mac is back."
National polls show Obama leading McCain by about 7 percentage points.
According to CNN's average of national polls, 5 percent of voters are still undecided.
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.
"You and I together, we'll change this country. We'll change the world."
There were a few boos when Obama mistakenly said Republicans were spending a lot of money on attack ads "here in Ohio."
Obama corrected himself, saying, "I've been traveling too much."
The senator from Illinois warned against overconfidence as the campaign nears its end. Watch an iReport debate: Who's best? »
"Don't believe for a second this election is over. Don't think for a minute that power will concede anything without a fight. ... We have to work like our futures depend on it in the next 24 hours, because it does," he said in Jacksonville.
Earlier Monday, McCain addressed a small crowd in Tampa, estimated at about 1,100 people.
Local reporters pointed out that just before the 2004 election, President Bush drew about 15,000 at a nearby location.
According to CNN's average of state polls, Obama holds a slim lead of 2 percentage points over McCain in Florida, 48 percent to 46 percent.
Both candidates vowed to bring about change in op-eds published Monday in The Wall Street Journal.
"After the difficulties of the last eight years, Americans are hungry for change and they deserve it. My career has been dedicated to the security and prosperity of America and that of every nation that seeks to live in freedom. It's time to get our country, and our world, back on track," McCain wrote.
Obama said that with him, voters can choose "the promise of change over the power of the status quo."
"So tomorrow, I ask you to write our nation's next great chapter. I ask you to believe -- not just in my ability to bring about change, but in yours. ... If you give me your vote, we won't just win this election -- together, we will change this country and change the world," he wrote. See state-by-state polling
Following his events in Florida, Tennessee and Pennsylvania, McCain traveled to Indianapolis, Indiana; Roswell, New Mexico; and Henderson, Nevada. He ended the day in Prescott, Arizona. Watch Sen. McCain in New Mexico »
Palin was attending rallies in cities in five states: Lakewood, Ohio; Jefferson City, Missouri; Dubuque, Iowa; Colorado Springs, Colorado; and Reno and Elko, Nevada. Latest battleground polls
In Missouri, Palin told an audience that a government run by Democrats would "gut" defense spending.
"So what do they think?," Palin said, referring to Democrats. "Do they think that terrorists have all of a sudden become the good guys? And changed their minds? No, the terrorists still seek to destroy America and her allies and all that it is that we stand for: freedom, tolerance, equality. The terrorists have not changed their minds." Watch Gov. Palin talk energy »
Her question was new, but Palin was pushing an argument she has made frequently in the closing week of the campaign: that some Democrats in Congress, led by Rep. Barney Frank, favor cutting the defense budget by a fourth.
Following the Nevada appearances, Palin was expected to fly to Alaska, where she planned to cast her ballot Tuesday morning.
With the exception of Pennsylvania, Bush carried each of the states that McCain and Palin planned on visiting Monday. iReport.com: Share your election experience
Obama's final day takes him to three Southern states that voted for Bush. In addition to his Jacksonville event, Obama also scheduled events in Charlotte, North Carolina, and Manassas, Virginia.
Obama's running mate, Sen. Joe Biden, was campaigning in Ohio, Missouri and Pennsylvania. Watch Sen. Biden's rally in Philadelphia »
On Monday night, both presidential candidates will have interviews air on ESPN during halftime of "Monday Night Football."
The poll of polls consists of nine surveys:
• CNN/ORC (October 30-November 1).
• Pew (October 29-November 1).
• CBS (October 28-31).
• Fox/Opinion Dynamics (October 28-29).
• ABC/The Washington Post (October 29-November 1).
• Reuters/C-SPAN/Zogby (October 30-November 1).
• Gallup (October 30-November 1);
• Diageo/Hotline (October 30-November 1).
• IBD/TIPP (October 29-November 1).
It does not have a sampling error.