Montgomery Blair, 1813–83, U.S. Postmaster General (1861–64), b. Franklin co., Ky., son of Francis P. Blair (1791–1876). He resigned from the army in 1836 after serving against the Seminole and settled in St. Louis as the legal and political protégé of Senator Thomas H. Benton. A successful lawyer and mayor of St. Louis (1842–43), he moved to Washington, D.C., where he was the first U.S. solicitor in the Court of Claims and made many appearances before the U.S. Supreme Court, including one as counsel for Scott in the famous Dred Scott Case. His antislavery views brought him to the Republican party, and he became Postmaster General in the Lincoln cabinet. To appease the radicals in the cabinet, the President forced his resignation before the election of 1864. Opposed to radical Republicanism, he returned to the Democratic party and was one of Samuel J. Tilden's counsel in the disputed election of 1876.
See W. E. Smith, The Francis Preston Blair Family in Politics (1933); B. J. Hendrick, Lincoln's War Cabinet (1946).