Walker, ROBERT JAMES (1801-1869), an American politician, born at Northumberland, Pa. He graduated at the University of Pennsylvania and practiced law at Pittsburg. In 1826 he removed to Mississippi, where he became prominent as a lawyer and as an opponent of nullification and secession. In 1835 he was elected to the United States Senate as a Democrat, and in that body he was one of the few outspoken anti-slavery advocates in his party. He became a close friend of President Tyler and greatly influenced the policy of his administration. In 1845 Walker was appointed secretary of the treasury, and he was responsible for the tariff bill of 1846. In 1857 he was appointed governor of Kansas Territory, but resigned in the following year, on account of the passage of the Kansas-Nebraska Bill. He earnestly advocated union after the outbreak of the Civil War and was a representative of the United States in Europe for a time, probably preventing the negotiation of a loan by the Confederate government. On his return he opposed the impeachment of Johnson.