Buchanan returned to the United States and was elected to the United States Senate by the state legislature to succeed William Wilkins , who had himself replaced Buchanan as the ambassador to Russia . Buchanan won re-election in 1836 and 1842 . The Jacksonian Buchanan opposed the re-chartering of the Second Bank of the United States and sought to expunge a congressional censure of Jackson stemming from the Bank War . He also opposed the gag rule , stating , " We have just as little right to interfere with slavery in the South , as we have to touch the right of petition . " Buchanan thought that the issue of slavery was the domain of the states , and he faulted abolitionists for exciting passions over the issue . His support of states ' rights was matched by his support for Manifest Destiny , and he opposed the Webster – Ashburton Treaty for its " surrender " of lands to the United Kingdom . Buchanan also argued for the annexation of both Texas and the Oregon Country . In the lead-up to the 1844 Democratic National Convention , Buchanan positioned himself as a potential alternative to former President Martin Van Buren , but the nomination instead went to James K. Polk
1844 Democratic National Convention
1844 Democratic National Convention
James Buchanan