Final answer:
The Copperheads were a faction of Peace Democrats in the southern Midwest and northern cities, opposed to the Civil War and Lincoln's policies, especially emancipation. They sought an immediate peace and favored a 'white man's' United States. They were named to suggest they were as dangerous as venomous snakes.
Step-by-step explanation:
The Copperheads were a faction of Peace Democrats during the American Civil War, particularly strong in the southern Midwest and among immigrant Catholics in northern cities. They were characterized by their opposition to the war and their strong desire for an immediate peace with the Confederacy, even if it meant ousting President Abraham Lincoln. With prominent figures like Ohio Representative Clement Vallandingham, the Copperheads expressed discontent with emancipation and preferred a United States that remained predominantly for the 'white man.' They had access to several newspapers to disseminate their views and were often associated with antiwar and anti-Lincoln sentiment. Republicans named them Copperheads to suggest treasonous behavior, drawing a parallel with the venomous snake.
The Copperheads were strongest in the southern Midwest, an area that included states like Ohio, Indiana, and Illinois, where there was strong antiwar sentiment. This group was critical of Lincoln's policies, especially emancipation, and they were part of a broader peace movement in the North that gained traction as the war dragged on and the public grew war-weary.