"It was labor that helped build the largest middle class in history. So, even if you're not a union member, every American owes something to America's labor movement," said Obama, whose run for the presidency was energized in no small part by unions.

Obama asserted that "our recovery plan is working," but repeated that he won't be satisfied until jobs are much more plentiful.

Shortly after taking the oath, Obama confronted a rapidly deteriorating economy, a clogged credit system, failing or ailing banks and a a shaky stock market. He used his speech here to tick off a host of steps the administration has taken to steady the economy, and he made a special pitch for the health care overhaul he has pushed.

"We have never been this close," Obama said. "We have never had this broad an agreement on what needs to be done." He accused vested interests of trying to thwart it. Some union-circulated posters held up by audience members proclaimed, "Health Care Can't Wait."

For their part, some elements within the labor movement have indicated frustration with Obama, who traveled to Cincinnati to speak to a state AFL-CIO gathering, because some key items such as legislation making it easier for people to join unions has languished in Congress. To vigorous cheers, Obama made a pitch for the bill in his speech. He also noted that the first bill he signed into law was one guaranteeing equal pay for equal work.

Obama spent a good deal of his time extolling the virtues of the union movement.

"We remember that the rights and benefits we enjoy today were not simply handed out to America's working men and women. They had to be won," he said.

At one point before Obama spoke, some in the crowd broke into chants of "Fired up" and "Ready to Go."

Obama closed with a story about how that phrase became one of his campaign slogans, and appealed to the assembled union rank and file to for help. "Your voice can change the world. Your voice can get health care passed. Your voice will make sure the American worker is protected. You can build America. I need your help," Obama said as the audience broke into more chants.

Labor Secretary Hilda Solis accompanied Obama to Ohio, and the pair appeared in front of a large American flag, nine smaller ones and red, white and blue bunting. Local union organizers handed out 10,000 tickets for access to the area where Obama was to speak. The event was moved indoors to a music pavilion because of threatened thunderstorms.

Obama chose the Labor Day union picnic as the backdrop to announce his selection of Ron Bloom as senior counselor for manufacturing policy.

Bloom was senior adviser to Treasury Secretary Timothy Geithner as part of the auto industry task force since February. Bloom, a Harvard Business School graduate, previously advised the United Steelworkers union and worked as an investment banker.

Bloom will work with the National Economic Council to lead policy development and planning for Obama's work to revitalize U.S. manufacturing, the White House said.