The South opened fire on Ft. Sumter. They started the war. And they lost. Nothing will ever change that fact.
Only after Lincoln opened fire on them first by sending those warships to force them to submit.
You keep ignoring the fact that those warships triggered the attack, and that there was no intention to attack until reports came in that the warships had arrived to attack them.
Big guy says he's going to beat the shit out of the Little guy. Big guy takes a swing, and little guy tears into him, and you want to blame the little guy for starting the fight?
Nope. Big guy started the fight by taking a swing.