In my reading of history slavery didn’t become a factor or was made a selling point of the war until much later. It all was about states rights at first and the Confederacy wanted to go their own way. The debate about the “War of Secession” got pretty heated here over the years. :)
Skydancer: “In my reading of history slavery didn’t become a factor or was made a selling point of the war until much later.”
But protecting slavery was the major factor driving Deep South declarations of secession, and major changes in their Confederate constitution.
Of course, slavery did not start Civil War, neither did secession or tariffs or anything else sometimes listed by pro-Confederates.
What started Civil War was the Confederate military assault on Union troops in Union Fort Sumter.