Considering that the pretended confederacy declared war on the United States, it was certainly a war begun by the South. The South called for 100,000 soldiers before Lincoln called for 75,000. There was no reason for the south to withdraw. It was a temper tantrum. The slave power demanded the right to throw a temper tantrum when ever they wanted.
It doesn’t have legal merit. It doesn’t make sense. That is, still what they did.
By contrast, in 1775 England pretended the right to tax the colonies, and made war against them before the colonies declared that because of England making war, they were of right independent.
I think you are just rattling in the wind now.