Based on my research(since the choices were not given), the United States tried to influence Vietnam’s national elections in 1956 when they supported Ngo Dinh Diem as president in South Vietnam. H<span>e was then named Prime Minister of the State of Vietnam during the Nguyen dynasty.</span>
Democrat James K. Polk defeated Whig Henry Clay in a close contest turning on the controversial issues of slavery and the annexation of the Republic of Texas.