Pete Buttigieg has dropped out of the race to be the Democratic nominee in the U.S. presidential election.
Speaking to supporters Sunday, the former mayor of South Bend, Indiana, said he had made what he called the "difficult decision" to exit the contest.
He did not endorse any of the remaining candidates, but promised to do "everything in my power" to see a Democrat take over the White House in January.
Buttigieg was the first openly gay major party presidential candidate. He said he hopes he sent a message to every kid who is "marked as different," showing them they can become a leading presidential candidate "with his husband at his side."
Buttigieg finished a disappointing fourth place in Saturday's South Carolina primary, winning no delegates.
His campaign had gotten off to a strong start with a narrow win in the Iowa caucuses and a close second place finish in the New Hampshire primary.
But he later struggled to compete for support among moderates with former Vice President Joe Biden, who won in South Carolina and who has far greater support among African American voters.
Biden called Buttigieg's candidacy a "historic trail-blazing campaign," while former New York City Mayor Mike Bloomberg said the Buttigieg campaign made the Democratic Party "stronger and our nation better."
Both Massachusetts Senator Elizabeth Warren and Minnesota Senator Amy Klobuchar said they know Buttigieg will serve the country for many more years. Sanders also complemented Buttigieg for making history and running a strong campaign.
The candidates face a major test Tuesday when voting takes place in 14 states, including big prizes California and Texas, along with the U.S. territory of American Samoa.
Polls show Biden leading in seven states, Sanders in six, and Klobuchar ahead in her home state.
Tuesday will also be the first time Bloomberg's name appears on ballots after he skipped competing in the first four states last month.