Closing his case for the presidency,promised on Monday to restore economic prosperity and a sense of "higher purpose" to a tired, embattled nation.
"We are one week away from changing America," the Democratic presidential candidate proclaimed, campaigning with the confidence of a contender nearing victory.
Obama returned to the soaring oratory of his first days as a candidate. With the luxury of a lead in the polls, Obama's goal was to remind voters of why he ran in the first place - and how he differs from his Republican rival,.
"In one week, we can choose hope over fear, unity over division, the promise of change over the power of the status quo," Obama said. "We can come together as one nation, and one people, and once more choose our better history. That's what's at stake."
The campaign called Obama's speech nothing less than a closing argument. The jury is out, though, until the election on Nov 4., and McCain vows to pull out a late victory.
Obama made a strategic choice to give this speech in pivotal Ohio. He struggled to connect with working-class voters here during the primaries and lost the Ohio primary to New York Sen. Hillary Rodham Clinton. No Democrat has won the presidency without Ohio's support since John F. Kennedy in 1960.
Obama, an Illinois senator, has accused McCain of resorting to smear tactics in a desperate attempt to win votes.
"If you don't have a record to run on, then you paint your opponent as someone people should run away from. You make a big election about small things," Obama said to a raucous crowd at Canton's civic center. "Ohio, we are here to say, 'Not this time. Not this year.'"
Unlike at most of Obama's campaign events, the crowd waved small American flags instead of campaign signs, reports CBS News' Maria Gavrilovic. Not one campaign sign could be found in the Canton Civic Center. (Read more of Gavrilovic's report from the scene)
Polls show a tight race in Ohio, which tilted the 2004 race in favor of President Bush. ()
For his part, McCain's core theme in recent days has been that electing Obama would give Democrats, who are on track to increase their congressional majorities, dangerous control of the government.
"My opponent is out there working out the details with (House) Speaker (Nancy) Pelosi and (Senate Majority Leader) Harry Reid, their plans to raise your taxes, increase spending and concede defeat in Iraq," said McCain, who was also in Ohio. "We're not going to let that happen."
"If the American people want to get something done, that's not a bad idea." said Virginia Gov. Tim Kaine, a Democrat, said on CBS News' The Early Show. "Divided government gives everybody the ability to not do something and then point the finger at the other guy."
As the longest presidential contest in history nears a finish, Obama and McCain are dueling for the electoral riches of Ohio and Pennsylvania.
Going beyond the economic concerns that have dominated the campaign, Obama spelled out a foreign policy agenda that, again, painted him as a needed change from Bush and McCain.
Obama said flatly he would end the war in Iraq and restore America's moral standing.
"I will never hesitate to defend this nation," he said. "But I will only send our troops into harm's way with a clear mission and a sacred commitment to give them the equipment they need in battle, and the care and benefits they deserve when they come home."
Unlike in other key states, Obama has struggled to sustain a big lead in Ohio despite pounding McCain with TV ads and building a strong get-out-the-vote operation.
Ohio, which has 20 electoral votes, never really recovered from the post-Sept. 11 recession. Long a manufacturing bastion, Ohio has lost almost 250,000 factory jobs since 2000. The unemployment rate is at 7.2 percent, well above the national average of 6.1 percent.
Public polls show Obama comfortably leading in Pennsylvania, though private Republican surveys show a closer race.