...but the idea that the war entered into to end slavery is simply incorrect.The idea that the war *wasn't* about slavery from its very beginning in South Carolina is simply incorrect. Secession and the war was about slavery in the south, as can be seen in the Ordinances of Secession and the secessionist op-eds.
Interestingly enough, he said this to Congress on January 12, 1848.
“... Any people anywhere, being inclined and having the power, have the right to rise up and shake off the existing government, and form a new one that suits them better. This is a most valuable, a most sacred right—a right which, we hope and believe, is to liberate the world...”
You do know, I assume, that of the 13 Articles of Secession for the 13 states that had them (though only 11 actually seceded), only four even mentioned slavery? They were: Mississippi; Texas; Georgia; and South Carolina.
If you’re suggesting there was disagreement between the legality of slavery between SC and Lincoln you’re mistaken. Had SC not seceded, irrespective of motivation, there would have been no attemt to interfere with slavery in SC or any other slave state. if Lincoln is to be believed, a victory at First Manassas by the North would have been irrelevant to the institution.