Daddy & his people used to say that Lincoln didn’t have to
have that war. Slavery was on its way out before long
anyway.
...
Many felt that way about slavery including people in the South. However, secession was real, the taking of federal property by secessionists was real, and secessionists started the war.
Fort Sumter wasn’t federal property after SC took it back.
I seem to recall something about Federal troops crossing the Potomac River and invading the Commonwealth of Virginia. In fact, almost every battle was fought on Southern soil in defense against an invading US army. Not sure where you got this idea about secessionists starting the war. By its very definition, secessionists wanted to leave the Union - not fight for control over it.