If you mean the civil war, that wasn't to "keep them together": it was one side forcing the other to get back in line and give up its slaves. It was not a conflict where two somewhat equal partners work out their difficulties, it was a war where the central government fought down an insurrection and during witch the south got utterly devastated and was under occupation for 10 years.
You could also argue that the civil war was about restoring bodily autonomy to a group of people who had been enslaved and forced against their will by corporations and governments.
I’m sure that’s the view from white southerners. The view from black southerners would be a little different.
It’s like the folks who are all nostalgic about the 50s. Sure, they were great if you were a straight cis white man. Not so much if you were gay or trans or black.
If only the slaves had any appreciation to the important component they were in their slave master's culture, they'd probably complain a lot less and try harder to accommodate their agrarian needs.
