CBS News' Maria Gavrilovic reports:
"It is good to be back in New York!" the senator shouted to the crowd, which the campaign estimated at 24,000 people. "This is a magnificent crowd."
The crowd of mostly young New Yorkers waited for hours to enter Washington Square Park and hear the Senator speak.
"What's inspiring about these crowds is that you have people from every walk of life. You've got young people and old people. You've got poor folk and not-so-poor folk. You've got blacks, whites, Hispanics, Asians, and Native Americans. You've got gay and straight. You've got people with disabilities."
Obama also wasted no time taking jabs at the Bush administration "Many of you are here because you are sick and tired of George Bush. You are tired of Bush and Cheney!"
The Senator even took direct aim at Hillary Clinton. "Even your Senator of New York wasn't clear about the Yankees. Ah, I know who I am rooting for, the White Sox! I know my team!"
Although most of Obama's speech remained in line with recent campaign addresses, he spoke more about September 11th and worldwide image of the United States than he usually does.
"We have done great damage to America's security and America's image over these past six years," the senator said. "We remember 9/11, we remember the world rallying around us after the horrific events just a few miles away. And we said to ourselves we are going to change, and the world said we will change with you to prevent such a travesty from happening once again. And we frittered all that good will away."
Obama discussed his Iraq war policy and his timetable for troop withdrawal, as well as his level of experience.
"There are a couple of guys named Dick Cheney and Donald Rumsfeld who had two of the best resumes in Washington," he said. "Longevity does not guarantee good judgment. A long resume says nothing about your character."
The Senator ended the rally by describing what kind of president he would be and calling for change.
"I am reminded every single day of my life, if not by events then by my wife, that I am not a perfect man. And I will not be a perfect president," Obama said. "But I can guarantee you this, that I will always tell you what I think and that I will always tell you where I stand."