When the South seceded there was no Emancipation Proclamation. You don’t secede over something that does not exist. There was no 11th District Court sitting down in Atlanta telling the plantation owners to turn all their slaves loose. Nobody was confiscating slaves.
The South was sick of the Cotton tariff. They were sick of being on the short end of the stick economically. They were sick of the yankee’s hand in their pocket.
As your buddy James Carville would say “Its the economy stupid” :-)
Then why did they say it was over slavery in their Declarations of Secession?