AP Photo/Carolyn Kaster

DES MOINES, Iowa - At one point even feeling the need to wipe a tear from his eye, President Obama ended his presidential campaign Monday night with an emotional appeal to voters in the state that started it all, asking Iowans to help him finish what he started four years ago.

"We have made real progress over these last four years," the president told an estimated crowd of 20,000 standing outside in the bitter cold. "But Iowa we are here tonight because we have more work to do. We are not done yet on this journey. We have more road to travel."

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Just steps away from the campaign office set up for his improbable victory in the 2008 Iowa Caucuses, a nostalgic Obama told Iowans they taught him "to bet on hope."

"To all of you who have lived and breathed the hard work of change, I want to thank you. You took this campaign and you made it your own," he said as he wiped away a tear streaming from his left eye. Obama concluded the final event of his self-proclaimed "last campaign" by retelling the story of Edith Childs, the South Carolina woman who coined his "fired up, ready to go" rallying cry. It's the same anecdote he told in the final rally of his 2008 campaign.

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"That shows you what one voice can do. One voice can change a room. And if it can change a room, it can change a city. And if it can change a city, it can change a state. And if it can change a state, it can change a nation. And if it can change a nation, it can change a world," Obama said as he fought through a hoarse voice at his third rally of the day in as many states. The president said that he'd tried to arrange for Childs to attend this final rally, but she told him she still believed he could win North Carolina on Tuesday, and she was going to knock on doors to help get out the vote.

"Iowa, in 2008 your voice changed the world. And Edith Childs asked me to ask you that if you're willing to still stand with me tomorrow… If you're willing to make sure we finish what we started, she's pretty sure we'll win Iowa. She's pretty sure we'll win this election ," he continued to cheers and applause.

"She just had one question for you. Are you fired up?," he asked as the crowd chanted back "ready to go!" "Iowa, tomorrow let's remind the world just why the United States of America is the greatest nation on earth."