"Barack Obama and I will keep our promise," he told a crowd of more than 500 who gathered under a large shelter at Memorial Park in the state's capital.
Standing before the shelter's wood-paneled walls adorned with corn husks, the Democratic senator from Delaware said the state unemployment rate is at a 17-year 6.7 and that 137,000 Missouri families are living in poverty.
Before a group of 40 people seated on hay bales, he said an Obama-Biden administration would offer health care security and prevent residents' retirement savings from "vanishing."
Biden reached his highest decibel level when describing what he referred to as Republican attacks on himself and Barack Obama during the nation's previous presidential and vice-presidential debates.
"John McCain, you noticed, couldn't bring himself to look Barack Obama in the eye and say these things. In my neighborhood, if you want to say something about me, look me in the eye and tell me," he said, pointing a finger at the audience. "Say it to me. ... Say it to me straight on."
Biden went on to criticize McCain and Republican vice presidential candidate Sarah Palin for planning to offer tax breaks for corporate CEOs and underestimating the economy's woes.
He received a standing ovation after declaring, "We will end this war responsibly," pounding his forefinger on the lectern with each word. Biden also emphasized his son Beau's service in the military.
Many Democratic supporters and detractors made their way to the park long before dusk.
About an hour before Biden's address, Linda Eisinger, a third-grade school teacher from Jefferson City, said she was impressed by Biden's policies toward education, health care and the environment.
"I think he's exciting, and, living through many campaigns, he just seems like he has a vision for the country and will lead us in the right direction," Eisinger said.
Zachary Hopkins, a 51-year-old chef from Fulton, said he came to hear Biden's message and to "be part of change." As a black man, Hopkins said, with the Obama campaign, "There's a sense of pride, because he's black, but more so it's about the economic issues."
Democrats weren't the only ones gathered for the event. Bill Smith, a Jefferson City retiree, stood along side Democrats holding a hand-drawn poster that read "McCain is a true patriot."
"They sound like they are going to win, but I don't think that's a given," he said of the Democrats in the crowd. "We should have someone in there with leadership experience, and I don't see that on the other side of the fence."
Biden's 50-minute address reinforced former Columbia College president Don Ruthenberg's decision to vote for the Obama-Biden ticket.
"I'm just so impressed with this guy," Ruthenberg said. "He's answered all of my questions, and his enthusiasm was great."
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