There is an entire civil religion called Lost Cause Ideology which has defending the chattel slave system as a cornerstone of it's beliefs. It's the reason that there were so many confederate statues created in the 1920s-1970s, well after the end of the Civil War.
Oh, wow, a Wikipedia page about something created in the 1920s-1970s. I actually learned about this through the internet several years ago. Not once in my entire life growing up did I actually hear about it.
You don't hear about it, it's a term used by others to describe a set of ideals held by many white southerners. Just because you haven't heard of something doesn't mean it doesn't exist.
I’m aware of it but only through seeing folks online in comments (and generally they are folks not from the south) making me aware of it despite living in the the south for half a century.
No one I know down here wastes two brain cells dwelling on or “upset over the loss” from a war fought 160 years ago, but to read it online you’d think every other home has an altar to Robert E. Lee in a special alcove in their living room.
I am a white southerner and have been for more than five decades, in all that time I have never met a single person who holds this view. I think if it was “many” I’d have encountered at least one in that time.
Sure you get the random redneck flying a tattered confederate flag outside their broken down trailer, but ascribing an adherence set of ideal to a complex philosophical hero worshipping belief system is probably a bit of a stretch.
If you were an African-American Southerner at the time, wouldn’t you be more worried about locals, for this sort of thing? Baldwin Lee is a Chinese-American art professor from New York, I suspect people would not be too worried that he might be a secret confederate.
https://en.wikipedia.org/wiki/Lost_Cause_of_the_Confederacy