MYTH ALERT. The confederacy was never a sovereign country.
You need to check your history. 1861-1865, the CSA was a sovereign nation, parallel in most respects to the USA. We had our own President and legislature. Just because YOU deny it does not prevent it from being an historical fact.
Do you recognize Taiwan as a sovereign nation? I do. The US does. Same thing.
The CSA was conquered and absorbed into the USA.
Northern states had slaves until well after the War of Northern Aggression. The Emancipation Proclamation did nothing.