“Bottom line: Republican abolitionism was certainly a minority view in 1860 and 1861, but that was beginning to change in 1862 and by 1865 became the 13th Amendment law of the land.
Do you disagree?”
Yes...and you’ve articulated my position - the civil war did not start over slavery. It may have been a factor, but it wasn’t the driving factor.
So let me repeat some facts we see so often obfuscated:
The choice to start Civil War was made by Jefferson Davis, who could just as easily have chosen differently.
When Davis decided to start war, he was not thinking of slavery, or tariffs, or anything else except his need to defend, in his words, "...the integrity and jurisdiction of our territory...", and in so doing, convince at least four Upper South states to join his Deep South only Confederacy.
Those four states soon did join, doubled the Confederacy's white population, giving them at least a fighting chance to win the coming war...
After starting war at Fort Sumter, the Confederacy soon after formally declared war on the United States, at which point, all discussion of causes & effects becomes mute.
Now that war was on, the Confederacy must be defeated unconditionally, and slavery abolished, in Lincoln's considered opinion.