Vallandigham, Clement Laird (vəlănˈdĭghămˌ, –gămˌ) [key], 1820–71, American political leader, leader of the Copperheads in the Civil War, b. New Lisbon (now Lisbon), Ohio. He became (1842) a lawyer, was elected to the Ohio legislature (1845, 1846), and was editor (1847–49) of the Dayton Empire, a Democratic weekly. A strong upholder of states' rights, Vallandigham was a U.S. Representative from 1858 to 1863, being defeated for reelection in 1862. On May 1, 1863, in a political speech at Mt. Vernon, Ohio, he declared, among other things, that the Civil War was being fought not to save the Union but to free the blacks and enslave the whites. Gen. Ambrose E. Burnside, then commanding the Dept. of the Ohio, accused him of violating "General Order No. 38," which threatened punishment for those declaring sympathy for the enemy, and Vallandigham was arrested, court-martialed, and sentenced to imprisonment for the rest of the war. President Lincoln commuted the sentence to banishment behind Confederate lines. The Peace Democrats of Ohio nevertheless nominated (July, 1863) Vallandigham for governor, but he was defeated by John Brough. He made his way from the Confederacy to Canada, and from there he returned to the United States and was allowed to go unmolested. In the presidential campaign of 1864, the Democratic platform, representing his views, demanded immediate cessation of hostilities. Made commander of the Sons of Liberty (see Knights of the Golden Circle), he was the most prominent of the Copperheads. After the war he was an unsuccessful aspirant to Congress.
See biography by his brother, J. L. Vallandigham (1872, repr. 1972); study by F. L. Klement (1970).