The declarations of secession from each state who issued one, wherein they said why they were seceding. It should not come as a surprise slavery was mentioned… a lot.
The CSA constitution, which forbade any state from banning slavery, and noted that no newly admitted state could be a non-slave state.
The existence of West Virginia, who seceded from the state of Virginia (a CSA member) because they had no slaves owing to how poor they were, and thus no reason to fight to keep it. This display of states rights made the CSA big mad and they tried to take WV back over a few times during the war.
Which I find ironic because of all the coal miner disputes including the Battle of Blair Mountain where workers had an actual fight with guns against the owner’s lackeys and it got so bad that the fucking president had to send in troops.
One can also look at, in no particular order:
West Virginia was so cool before the modern day. Now instead of anti-slavery and miner agitation, it’s Confederate flags and corporate simping.
Which I find ironic because of all the coal miner disputes including the Battle of Blair Mountain where workers had an actual fight with guns against the owner’s lackeys and it got so bad that the fucking president had to send in troops.
And the entire state was shaped by the New Deal tree planting efforts.