Just so we're clear on this:
Throughout its existence as symbol of the Confederacy, the CBF protected slavery in Confederate territory not under Union Army control.
In Confederate regions under control of the US flag slaves were emancipated by Presidential proclamation.
And each year those Union regions grew in size until by April 1865 they covered most of the South.
After Unconditional Surrender in 1865 the United States ratified the 13th Amendment under its own flag, not the Confederate flag.
Right. Slavery was *STILL EXISTING* under the Union flag. A quite obvious bit of proof that eradicating it was not the reason for the invasion.
That bit of hypocrisy lingered awhile longer until Lincoln could threaten, bribe and cajole enough people into supporting that Amendment. Oh, and he put a gun to the head of all the Southern states and *FORCED THEM AT THE POINT OF A GUN* to pass that amendment.
But it's all Legitimate, and "consent of the governed" and all that ethical stuff. It wasn't Dictatorial at all.
The Evil people won that war. They murdered 750,000 people to do it, but what are human lives to Dictators?