(CNN) - Delaware Sen Joe Biden and Connecticut Sen. Chris Dodd abandoned their bids for the Democratic presidential nomination Thursday night.
"I count the past year of campaigning for the presidency as one of the most rewarding in a career of public service. Unfortunately, I am withdrawing from that campaign tonight," Dodd said in an e-mail message sent to supporters tonight.
"But there is no reason to hang our heads this evening - only the opportunity to look towards a continuation of the work we started last January: ending the Iraq War, restoring the Constitution, and putting a Democrat in the White House. ... You've been an invaluable ally in the battle, and I'll need you to stick by my side despite tonight's caucus results."
"I'm withdrawing from the presidential race, but let me assure you, we do not exit this race with our heads hanging," Dodd told his supporters Thursday night. "Rather, we do so with our heads very, very high."
Dodd received less than 1 percent in the Iowa caucuses, with 99 percent of precincts reporting.
The 5-term senator called his campaign "one of the most rewarding in my life of public service" and said the results, while not what he had hoped, "sent a clear message that his party is united in the belief that this nation needs change."
Biden sounded a similar note. In a speech before his supporters - who at one point chanted - "Joe, Joe," he said: "I ain't going away, let me make that clear." He said he had no regrets, and the reason he embarked on the campaign was because he believed in the nation. "There's no reason not to be happy," he said. "The promise of this nation is immense." He said he plans to return to the Senate as head of the Foreign Relations Committee.
Meanwhile, New Mexico Gov. Bill Richardson - who will finish a distant fourth in Iowa, with roughly 2 percent of the vote - is staying in the race. "We are on the way to New Hampshire tonight. We plan to make this a referendum on the Iraq war. This is far from over," Press Secretary Tom Reynolds tells CNN's Suzanne Malveaux.
Richardson Communications Director Pahl Shipley confirms the news, adding that "New Hampshire is a new game. Every vote counts."
Related video: Biden drops out
Related video: Dodd drops out
– CNN's Mark Preston and John King