Pabianice-good link on the Previous Copperheads:
The most prominent Copperhead leader was Clement L. Valladigham of Ohio, who headed the secret antiwar organization known as the Sons of Liberty.....at the Democratic convention of 1864....Vallandigham persuaded the party to adopt a platform branding the war a failure, and some extreme Copperheads plotted armed uprisings...assured Lincoln’s reelection, and the plots came to nothing...with the conclusion of the war in 1865 the Peace Democrats were thoroughly discredited. Most Northerners believed, not without reason, that Peace Democrats had prolonged war by encouraging the South to continue fighting in the hope thatthe North would abandon the struggle.
Source: “Historical Times Encyclopedia of the Civil War” Edited by Patricia L. Faust