Candidates for Illinois governor and the president's former Senate seat are locked in tight races. Mr. Obama made a last-ditch plea for Democrats to turn out on election day.
When the president mounted the Midway Plaisance stage, the crowd estimated at 35,000 roared approval of its hometown hero.
"Hello, Chicago!" the president said. "It's good to be home."
The rally was Obama's first public appearance in Chicago since election night 2008 in Grant Park. Saturday night, he used that moment in history as a way to inspire Illinois voters.
"If everybody who fought for change in 2008 shows up in 2010, we will win this election," Obama said. "In three days, you can say, 'Yes, we can!'"
The president Obama urged voters to defy expectations and tamp down a Republican tide that many people expect to crest in Tuesday's elections.
"Chicago, it's up to you to let them know that we have not forgotten; we don't have amnesia," the president told a large outdoor crowd near his home, referring to the economic recession that hit during George W. Bush's presidency. "This election is a choice between policies that got us into this mess and the policies that are starting to lead us out of this mess."
Hours earlier, the president led get-out-the-vote rallies in Pennsylvania and Connecticut, warning that without a Democratic voter surge, Republicans could rollback health care and financial industry reforms accomplished during his first two years in office.
"We could fall short, and all the progress that we've made over the last couple of years can be rolled back," said Mr. Obama.
Actor and spoken word artist Common warmed up the crowd, which also heard from Gov. Pat Quinn and U.S. Senate candidate Alexi Giannoulias.
"We got any Democrats in the house?" Giannoulias asked the crowd. "I can't hear you. We got any Democrats in the house?"
The first speaker to warm up the Hyde Park crowd was none other than Chicago Mayor Richard Daley. The mayor has been keeping a lower profile since he announced he would not seek a seventh term, but he showed up Saturday evening to help the Democratic Party.
The evening rally was the highlight of several such events around the city of Chicago on Saturday.
Earlier in the day, the Chicago-area Democratic get-out-the-vote effort concentrated itself at RainbowPUSH headquarters, where appearances by the party's candidates dominated the weekly meeting.
"In order to help the President move this country forward, we need all of you to get out and vote, to remind everyone what's at stake," said U.S. Senate hopeful Alexi Giannoulias Saturday morning.
"I'm a Democrat. We need to stick together. We cannot have, in this critical election, right-wing Republicans take over," Gov. Pat Quinn said.
The Chicago Federation of Labor (CFL) is staffing a get-out-the-vote phone bank at a South Side union hall. The CFL says has already contacted one-half million voters.
Democrats say they believe if they motivate their base in Illinois, they cannot lose.
"Don't you to listen to no pollster. Don't you believe the change ain't coming!" said U.S. Rep. Jesse Jackson Jr. "Stop complaining, and get out and vote!"
Barack Obama won Illinois by 25 percentage points in the 2008 presidential election. While Democrats do not expect anywhere near the turnout of two years ago, Obama and party leaders felt a need to motivate their base for next Tuesday.
Within minutes after the rally ended, a spokesman for the Republican National Committee called the Democratic rally turnout lackluster. TheRNC quoted one observer who counted only 20,000 people in attendance. However, there appeared not to be any more space for any additional people in the area that was assigned for the president's rally at the University of Chicago.
ABC7 was told after the rally that Mr. Obama was not inside his Kenwood home but out with friends having dinner at a River North restaurant.
(The Associated Press contributed to this report.)