President Biden announced Sunday he would drop out of the presidential race, making him the first president since 1968 to not seek re-election.

Biden made the announcement on Sunday afternoon, with just 183 days left in his term, and 29 days before the Democratic National Convention on Aug. 19, 2024.

On March 31, 1968, President Lyndon B. Johnson announced he would not seek re-election with 295 days left in his term, and 148 days until the party convention.

Before that, President Harry S. Truman announced he would not seek another term on March 29, 1952, and Calvin Coolidge announced he would not seek re-election on Aug. 2, 1927.

In U.S. history, only three presidents made and kept their promises to serve only one term.

President Rutherford B. Hayes announced in advance that he would serve only one term, and when his term was up he retired to Spiegel Grove, his home in Fremont, Ohio, in 1881.

President James Buchanan was another president who promised to serve only one term, and at the time, the nation was facing turmoil over slavery and nobody asked him to rescind his pledge.

Finally, President James K. Polk kept his promise to not seek a second term. He was succeeded in office by Zachary Taylor, a hero from the Mexican War and a member of the opposing Whig Party whom Polk despised.