After Franklin Pierce won the 1852 presidential election , Buchanan agreed to serve as the United States Ambassador to the United Kingdom . Buchanan 's service abroad conveniently placed him outside of the country while a debate over the Kansas – Nebraska Act roiled the nation . While Buchanan did not overtly seek the 1856 Democratic presidential nomination , he most deliberately chose not to discourage the movement on his behalf , something that was well within his power on many occasions . The 1856 Democratic National Convention met in June 1856 , writing a platform that largely reflected Buchanan 's views , including support for the Fugitive Slave Law , an end to anti-slavery agitation , and U.S. " ascendancy in the Gulf of Mexico . " Buchanan led on the first ballot , boosted by the support of powerful Senators John Slidell , Jesse Bright , and Thomas F. Bayard , who presented Buchanan as an experienced leader who could appeal to the North and South . President Pierce and Senator Stephen A. Douglas also sought the nomination , but Buchanan was selected as the Democratic presidential nominee on the seventeen ballot of the convention . He was joined on the Democratic ticket by John C. Breckinridge of Kentucky
1856 Democratic National Convention
1856 Democratic National Convention
Presidency of James Buchanan