George Mifflin Dallas was a U.S. senator from his home state of Pennsylvania and the 11th vice president of the United States. Born in Philadelphia, Dallas studied law and was admitted to the bar in 1813. He then became private secretary to Albert Gallatin, U.S. minister to Russia. Returning to Philadelphia, Dallas held office as mayor, then was U.S. attorney for the eastern district of Pennsylvania. He was elected in 1831 to fill the 14 months of the unexpired term of Pennsylvania Senator Isaac D. Bernard. He chose not to run for reelection, but remained active in Pennsylvania state politics. In 1837 President Martin Van Buren appointed Dallas envoy and minister to Russia, an office he held for two years.
Dallas was James K. Polk's running mate on the 1844 Democratic ticket that defeated Whig Henry Clay. In his capacity as president of the Senate, Vice President Dallas cast a tiebreaking vote repealing an existing protective tariff. Although traditionally known as a protectionist during his Senate years, he supported the administration's efforts to reduce tariffs, and defended his actions as appropriate to public sentiment.
As U.S. minister to Great Britain from 1856 to 1861, Dallas conducted negotiations leading to the Dallas-Clarendon Convention, which sought to settle conflicts between the two countries over relations with Central America. He also resolved an historic dispute with Great Britain over that nation's search of American vessels. In retirement, the former vice president wrote a biography of his father, Alexander J. Dallas, secretary of the treasury from 1814 to 1816, and published volumes of his own letters and opinions. He died in Philadelphia in 1864.