If you shoot up my dog house to begin the whole thing then don't complain if I come after you, regardless of whether you are on your property or mine.
The south initiated hostilities by firing on Sumter. They started the war so they had nothing to complain about when the war came home to them.
If that dog house is (a) sitting in the middle of my front yard and (b) inhabited by a hostile dog that threatens my free use of that yard, I am completely within my rights to seek to remove it - even if you own the dog and the wood in which he resides. And when you come over with your shotgun to assist that dog in inflicting harm to me should I try to remove him and his house from my yard and, upon your arrival, procede to fire a warning shot in the sky when one of my friends drops by to visit, you have no reasonable grounds on which to expect me to continue to tolerate that dog house's presence.
The south initiated hostilities by firing on Sumter. They started the war so they had nothing to complain about when the war came home to them.
Your logic is, as usual, a non-sequitur. The principle of causality dictates that there was no necessity in the southern actions at Sumter that caused the war of invasion to happen. Invasion of the south did not have to happen as a result of Sumter. The events have no necessary connection between each other - only a relationship of proximity and indirect influence upon other direct causes. Rather, the war itself, which occurred by way the northern invasion of the south, was a necessary consequence of only the choice that made it so - the choice to invade. That choice was made by Abraham Lincoln, who thus bears ultimate responsibility for the war's occurrence. Some of his idolaters do not like him having to bear that responsibility and, seeing as he attempted to escape it himself by blaming his sinful war on God, it is not unexpected that they do so. Yet that responsibility remains with Lincoln, the direct cause of the war.
Better learn some history.
The north didn't have the guts to start anything so they used deception to make the south believe that a war had begun and that the north had attacked. Only then did the south fire on Sumter.