[bravo whiskey]

a copperhead was a member of the opposition party who thought the war couldn't be won and cost too much. they wanted to end the war. they hated the president, libeled and mocked him all the time, thought he was stupid. they had more sympathy for the enemy then for their own country. they thought the black man was too stupid to live on his own and certainly not worth fighting for. they had a failed military man as their presidential candidate. they had numerous newspapers and media condemning the administration. this was in 1864.
let's compare with today. no difference. democrats were copperheads then, they are copperheads now.

[NewRomeTacitus]

Excellent, I forgot all about that! And we think our modern factions are complicated.

Thanks for sharing the lore. "Politically correct" indoctrination would otherwise have us forget it.