Copperheads were a faction of the Democratic Party in the northern United States during the American Civil War. They opposed the war and advocated for an immediate peace settlement with the Confederacy. Their name was derived from the venomous snake, symbolizing their perceived treachery. The Copperheads were particularly active in the Midwest, where they gained support among those who were discontented with the war's progress and its impact on the economy. Prominent leaders included Clement Vallandigham, who famously criticized the Lincoln administration and its policies. Their influence waned as the war continued and public sentiment shifted.