I keep explaining to you how you are wrong, and you keep ignoring the *EVIDENCE* which I show you.
The South launched a war of violent secession
This is incorrect. The first act of violence was Major Anderson kidnapping a Southern ship captain and forcing him to carry his troops to Sumter, and in the process burning the guns at Fort Moultrie. This is after the Secretary of War had informed South Carolina that all the installations would be turned over to them.
The Second act of Violence was Abraham Lincoln ordering a fleet of warships to fire on the people of South Carolina if they did not *SUBMIT* to his continued occupation of their land, and the continued collection of taxes from them.
So you see, you are incorrect. The people of South Carolina did not start the war. Abraham Lincoln started the war, and he did so deliberately.
His orders to Lieutenant Porter had Porter opening fire on Southern ships, with Porter having no knowledge of events in South Carolina. Had Lincoln not started the war in Charleston, Porter would have been credited with starting it in Pensacola.
You need to stop believing crap, and start understanding the truth of what happened.
to preserve an economic system based on the use of slave labor
And this is just a lie. The existing economic system under the United States government would have remained a slave based system.
Stop lying to us by telling us the South was changing something. No, they were keeping things exactly as they had always been under the USA. They weren't changing a d@mn thing.
*THIS* was the United States for "four score and seven years." 
Stop trying to pretend that slavery wasn't the normal condition of the United States of America. In fact, Slave states existed in the USA longer than they did in the Confederacy.