Myer - this is not a defense of the South's slavery problem. If they had set an Emancipation date then the war would have went better for them.
The war between the states was largely about taxation and self determination.
The Union offered a continuation of slavery for a set period of time if the Confederacy came back.
The Union had four slave states in it -Missouri, Kentucky, Maryland, and Delaware and did absolutely nothing to end slavery in those states until the closing of the war and the final version of the 13th amendment.
On top of that - Read the Emancipation Proclamation - it excluded freeing slaves in territory that the Union held at that time. The Union held parts of Louisiana at the time of The Emancipation Proclamation, and those slaves were not freed until the end of the War.
In Sherman's Razing of the South - and the March to the sea he REFUSED to free slaves and turned them back to the care of the land owners.
The War might have been in part about freeing the slaves, but if you read archival data, many Norther papers leading up to and after the secession said they would not put up with losing the moneys that came into the Federal Coffers through imposts, duties, tariff's etc.
The "south", while being a large land mass was lightly populated compared to the north. While being a fraction of the population, they paid above 70% of what went into the Federal Government.
Only five percent of the Southern population owned slaves, something like only 2% owned large numbers. (Another case of the Wealthiest 2% causing most of the issues?)
So 95% of the population did not own any slaves and had no dog in that fight.
Slightly above half of the Southern population wanted slavery to end - for reasons from moral reasons to self interest.
My Father's branch of the family arrived here after the war - and cousins of his branch were on both sides of the conflict - ancestors from my mom's side of the family fought on the Union side. So my stake in this argument isn't rooted in some ancestral memory of Dixie.
I view this as a cautionary tale, and an example of how 'Murrica did one thing right - by accident, really, and did more things wrong.
Virginia, North Carolina and Tennessee wished to be Neutral, and only joined the Confederacy when they were told they would have to provide conscripts and Militia and allow the Union forces to march across their states.
I would make the argument that if Southern States had not mentioned maintaining slavery as part of their Secession Declarations then a lot of the Union States would have been less inclined to participate. That's true because there were newspaper editorials in states like Ohio and Indiana that stated that the idea of the war was unpopular, and only palatable because they didn't like slavery.
Going into conjecture led by statements of the time - had the Confederacy set an emancipation date then countries like Great Britain would have sided with them, at least to the point of the Royal Navy protecting British Shipping into Southern Ports.
Lee, like Grant wasn't a slave owner per se but became one by marriage. (Grant married a Missouri daughter of a slaveowner)
On the flip side Grant, Sherman, Sheridan statements say they were fighting only for reunification, and thought the abolition movement was filled with idiots and crazy people.
If you look at actions of the Union army - long before Sherman's march through Georgia the notion of the War Between the states being waged for moral or humanitarian reasons is laughable.
If you surrender a civilization to avoid social disapproval, you should know that all of history will curse you for your cowardliness - Alice Teller
If John of Patmos would browse the internet today for half an hour, I don't know if the Book of Revelations would be entirely different or entirely the same.