The impact that movie had has never been repeated. As a child my Nana and Taid told me stories of how they got to see the film. They had to sneak into the theatre and stand at the back as even the aisles were full of people sitting on the floor.
When it was re-released in the 80s I had to see it, took my Grandparents as a treat, but was a bit underwhelmed if I am honest.
Its a tricky one this. A film about the Civil War will obviously reflect the attitudes of the era. But a film made in the late 30s should really have some balance to that. Unless Ashley mouthed some platitudes I dont recall much discussion about slavery and I seem to recall that there is a Klan raid where Butler gets hurt.
I think its that unquestioning stance that folk object to, the protagonists lived gilded lives carried on the backs of the "loyal darkies" like the girl who won the Oscar.
I think the problem was that it showed the south as a noble society, and how the poor plantation owners suffered when no one was compelled to wipe their asses for them anymore. Boo-fucking hoo.
My solution would be simple. Make it a double bill for balance. Before they get to see
Gone with the Wind, they have to sit through a showing of
Mandingo. Which was probably more historically accurate.