Republican Fred Thompson on Tuesday quit the presidential race after weak showings in early primary and caucus states.
"Today, I have withdrawn my candidacy for president of the United States. I hope that my country and my party have benefited from our having made this effort," Thompson said in a statement.
The former Tennessee senator, who had been considering whether to continue after his third-place finish in South Carolina, was also facing depleted campaign coffers.
He did not say which former rival he would endorse, although he supported John McCain in 2000 against George W. Bush.
Thompson had entered the race with great fanfare, consistently ranking among the top Republicans in national polls and state surveys. But he began his bid some eight months after his eight rivals began their campaigns.
He was plagued by lackluster fundraising, high-profile staff departures, and what some observers said were weak performances on the stump. Critics also accused him of being lazy and running a light campaign schedule.
He is perhaps best known to millions of Americans as gruff district attorney Arthur Branch on NBC's crime drama Law & Order, as well as for his roles in more than a dozen movies.
During his 1994-2002 Senate tenure, he was considered a reliably conservative vote. However, he did stray from the party line on a few issues, including advocating for campaign finance reform.
In Florida, McCain, former Massachusetts governor Mitt Romney and former New York mayor Rudy Giuliani are battling for the lead ahead of its Jan. 29 primary, while former Arkansas governor Mike Huckabee is evaluating his next steps amid money troubles of his own.