though belmont lobbied hard for it, buchanan denied him the ambassadorship to spain after his election in 1856, thanks to the ostend manifesto. as a delegate to the 1860 democratic national convention, belmont supported stephen a. douglas, who subsequently named belmont chairman of the democratic national committee. belmont energetically supported the union cause during the civil war as a war democrat, helping missouri congressman francis p. blair raise and equip the union army's first mainly german-american regiment. belmont also used his influence with european business and political leaders to support the union cause in the american civil war, stopping the rothschilds and other bankers from lending to the confederacy and meeting personally with the british prime minister, lord palmerston, and members of napoleon iii’s government.