Final answer:
The term "Peace Democrats" was also known as Copperheads, a faction of the Democratic Party that opposed the Civil War and pushed for a peace settlement with the Confederates.
Step-by-step explanation:
The term "Peace Democrats" was also known as Copperheads. They were a faction of the Democratic Party during the American Civil War who opposed the war and wanted an immediate peace settlement with the Confederates. Notably, these Peace Democrats were labeled Copperheads by their political opponents, the more ardently pro-war Republicans, as a way of likening them to the venomous snake. The Copperheads drew support primarily from the southern Midwest and immigrant Catholics in northern cities. With figures like Ohio Representative Clement Vallandigham leading their cause, the Copperheads heavily criticized Lincoln, his administration, and emancipation, and were a force against the Republicans' anti-slavery measures in Congress.