Two hundred years after Congress first sat, Nancy Pelosi cracked what she called the "marble ceiling" of the U.S. Capitol Thursday, as she was introduced as America's first female Speaker of the House.

Nancy Pelosi, left, Harry Reid, right, and Sen. Charles Schumer, chairman of the Democratic Senatorial Campaign Committee, share an election night celebration with fellow Democrats on Nov. 7.
(J. Scott Applewhite/Associated Press)

To cheers and applause, Pelosi took her seat at the Speaker's podium and accepted the gavel of the House of Representatives from minority House leader John Boehner.

"I accept this gavel in the spirit of partnership, not partisanship, and I look forward to working with you … for the good of the American people," Pelosi said in her prepared remarks.

"In this House, we may belong to different parties, but we serve one country, and our pride and our prayers are united behind our men and women in uniform."

While the meeting of the new U.S. Congress Thursday marked a power shift that put control of the House and the Senate in the hands of Democrats for the first time in a dozen years, the day belonged to Pelosi.

The Democratic representative from California officially became the highest-ranking woman to ever sit in political office and third most powerful politician in America.

With her grandchildren joining her for the historic moment, Pelosi beamed as her name was placed in nomination and the party roll call began. Her election to Speaker came after a vote of 233-202, the chamber's Democratic-Republican breakdown.

'The sky's the limit'

"For our daughters and our granddaughters, today we have broken the marble ceiling," she said at the podium. "For our daughters and our granddaughters, the sky's the limit."

With the welcoming of the 110th Congress, Democrats and Republicans pledged co-operation in spite of their ideological differences.

The Democrats have promised to pursue an aggressive agenda in the first 100 hours of business, including pushing legislation to raise the minimum wage, increase stem cell research and cut interest rates on student loans.

The legislation isn't expected to be open for much debate or amendment by the Republicans.

"It appears the 'first 100 hours' of the Democrats' legislative agenda will come from a smoke-filled room," said Republican House Representative Jeb Hensarling.

Democrats defended the move, saying they are merely delivering on election promises.

Pelosi has promised immediate steps to ban gifts from lobbyists and to clamp down on travel funded by private interests.

In his opening remarks as the new Senate majority leader, Nevada Democrat Harry Reid said he hoped all sides would "work in a bipartisan basis in an open fashion to solve the problems of the American people."

Iraq war a focus

The mid-term election results were seen as an indictment of U.S. President George W. Bush's Iraq policy.

"If I was going to quantify it, I would say it was maybe 60 per cent Iraq, 35 per cent scandals and five per cent other things," said longtime political analyst Charlie Cook, who believes the Democrats might be missing the point about why they were swept back to power.

Democrats promised a new direction on Iraq throughout the mid-term election campaign, but two months after the vote, the party has yet to deliver any plans.

Bush on Wednesday urged both parties to set aside partisan politics and work together to "focus on the future." He also said he was working on a five-year plan to balance the budget by 2012.

Bush, who said he looked forward to working with the new Congress, challenged Democrats to avoid passing "bills that are simply political" statements.

Other priorities Democrats have pledged to tackle during their first 100 hours include:

• Require the government to negotiate with pharmaceutical companies for lower Medicare drug prices.
• Create an intelligence oversight panel within the House Appropriations Committee and implement the 9/11 Commission recommendations.
• Promote renewable energy and conservation and repeal a handful of oil industry tax breaks.
• Expand current bans on some privately financed trips, eliminate gifts from lobbyists, prohibit travel on corporate jets and require greater public disclosure of targeted special interest legislation.

With files from the Associated Press