She commended her opponent, saying that it was the first campaign in the state where two women ran for a U.S. Senate seat.
Gillibrand also spoke about the devastation the state had seen after Sandy, promising that New Yorkers "will rebuild better and stronger."
"Sen. Gillibrand has proven herself to be an absolute . . . force in the United States Senate," said Assemb. Keith Wright, co-chair of the New York State Democratic Party. "Kirsten has delivered by working across the aisle."
Earlier in the night, Republican party officials had said Long's campaign -- even if she lost -- will be judged as successful. In a 10 minute speech, Long conceded the race, thanking "allies in the Tea Party."
Long said, "I'm disappointed that Sen. Gillibrand never really engaged on the main issues that confront New York and Americans in this campaign." She cited the national debt, taxes and other economic factors.
"Kirsten Gillibrand is put on notice now" that she will be challenged in the future, said David Laska, a spokesman for the Republican Party of New York State.