His remarks follow a central theme he has pursued ever since declaring his candidacy: harnessing the federal government to help those at the bottom or middle of the economic ladder.
In August, he honored the 50th anniversary of the March on Washington by calling for economic equality what he called a crucial step to long sought-after racial equality.
Much of the 50-minute speech in a low-income area of Washington, D.C., touched on how changes in technology and globalization have hurt jobs and benefits for many while enriching others. The top 10 percent of wage-earners, who used to take in one-third of the nation's income, now take in half, he said.
"There's a dangerous and growing inequality and lack of upward mobility that has jeopardized middle-class America's basic bargain: that if you work hard, you have a chance to get ahead," he said.
Obama said solutions draw on the actions of past presidents, including Abraham Lincoln, Theodore Roosevelt and Franklin D. Roosevelt, who developed programs, such as land-grant colleges, Social Security and protections for workers.
He called on lawmakers to extend jobless benefits for 1.3 million long-term unemployed Americans that expire in a few weeks.
Obama did not recommend any new policies to help alleviate the income gap, but he pushed for programs he already had supported an increase in the minimum wage, expanding preschool initiatives, rewriting the nation's immigration laws and passing laws that would protect women and gays against discrimination all of which have been met coolly by Republicans. Obama challenged Republicans Wednesday: "You owe it to the American people to tell us what you are for, not just what you're against."
Republicans responded that any economic failures are the president's fault.
"It should be no surprise why his approach has left more Americans struggling to get ahead," said Brendan Buck, a spokesman for House Speaker John Boehner, R-Ohio. "The president's economic policies promote government reliance rather than economic mobility."