DALLAS, GEORGE MIFFLIN an Ameri can statesman and diplomat, was United States minister to Eng land (1856-61) on the eve and at the outbreak of the American Civil War, and the immediate predecessor of Charles Francis Adams. He was the son of Alexander James Dallas (q.v.). In 1813, just after he was admitted to the bar, he went abroad as the private secretary to Albert Gallatin and brought back from Ghent important despatches from the American peace com missioners. For the next 20 years he played a prominent and fairly successful role as a Democrat in Pennsylvania politics and in the United States Senate; and from 1835 to 1839 was United States minister to Russia. When he returned from Russia, he entered upon a long struggle with James Buchanan for the party leadership in Pennsylvania. As candidate for vice-president on the ticket with James K. Polk (q.v.), he helped to win the Demo cratic victory in 1844; but the appointment of Buchanan as secre tary of state deprived him of a most important share of party patronage and influence in the Polk administration. Consequently he became the leader of a distinct body of conservative Demo crats who were not in all respects in harmony with the administra tion, but he did not go so far as to oppose territorial expansion. Indeed, he sacrificed his influence with protectionists in Penn sylvania by casting his vote at a critical time in the Senate in favour of the Walker Tariff bill of 1846. He returned to the practice of law in 1849, and became associated with Robert James Walker (q.v.), his relative by marriage, in promoting in England the financial interests of the Illinois Central railroad.
In 1853 President Pierce was urged to appoint Dallas minister to England; and in 1856 the President did so, sending him to succeed his old political rival, James Buchanan, who returned to the United States and made a successful campaign for the presidency. Buchanan retained Dallas at the London post throughout the whole of his administration. Dallas's earlier con tacts with the friends of the United States in Great Britain, through the promotion of American business interests there, ap pear to have served him well in the solution of difficulties which faced him from the beginning of his residence as minister. Fric tion over the various interpretations of the ill-starred Clayton Bulwer Treaty of 1850 and the serious crisis over British enlist ments in the United States during the Crimean War, which was drawing to a close, made war imminent between Great Britain and the United States ; but Cobden, Gladstone and others forced their Government to publish papers of a damaging character, while in America the failure of the Cincinnati Convention to nominate President Pierce for a second term had a pacific effect. In Great Britain the nomination of Buchanan was regarded by some as a stiffening of the American attitude. In October, Dallas and Lord Clarendon succeeded in drawing up the project for a treaty which later became the basis of an adjustment. By the close of 1860, official Anglo-American relations were to all appearances corn posed.
There is no satisfactory biography of George Mifflin Dallas; but see his Letters from London, 1856-186o (1871) ; his Diary (1892) ; and J. B. Moore (ed.), The Works of James Buchanan. (T. P. MA.)