The Commonwealth elected its first women to the U.S. Senate on Tuesday when Democrat Elizabeth Warren bested incumbent GOP Scott Brown. 

There was a joyous explosion at the Fairmont Copley in Boston, where thousands of supporters gathered for Warren's victory party.

While Sen. John Kerry and Gov. Deval Patrick took the stage, praising campaign workers and congratulating Warren, there was a persistent roar from the crowd. Strangers hugged each other and cheered until the Harvard professor took the stage. 

"This victory belongs to you," Warren told supporters, promising to fight for a level playing field and to put people back to work.

"We're going to hold the big guys accountable. … and that millionaires and billionaires pay their share. And to all the young people who did everything right and are drowning in debt, we're going to invest in you. ... And to all the women across Massachusetts … you better believe we're going to fight for equal pay."

The Senate campaign was an historic race for the Commonwealth, both in its bitter competition and spending totals. Fundraising records showed that Brown and Warren spent nearly $68 million pursuing the seat, according to the Associated Press.

Warren raised $38.5 million compared to Brown's $26.7 million. More money was raised from small donors than any Senate campaign in the history of the country. 

But the acrimony that characterized the election seemed to fade as soon as Warren was declared the winner, as early as 9:30 p.m., when only 40 percent of the state's precincts had reported. Brown's concession speech was gracious and so positive it could have been mistaken as a victory speech. 

"I don't want to see any sad faces," he told supporters at the Park Plaza Hotel in Boston. "I could not have asked for better allies and friends to see us through this battle. …We stand strong now even in this disappointment."

Brown congratulated Warren and, likewise, when Warren spoke, she asked her party to join her in thanking Brown. 

Warren closed her acceptance speech by acknowledging that 50 years ago on Election Day, Ted Kennedy was first elected to the Senate. She pledged to fill his seat with the same commitment to working families across the Commonwealth that her demonstrated over his 47 years of service.