In the American Civil War the North won, and by and large most folks in the North that I know don't give it a second thought anymore. Badger football is in Camp Randall stadium, and I doubt many fans realize the park memorializes a Union encampment/training ground. And when they do, they don't care. It's an ancient war. There are some customary attitudes one is supposed to have about it ("If this show were being performed in New York, he said, he’d think it was weird."), but little more. I can't speak for the South--I gather the hostility diminished over the years, and that in some circles there are customary attitudes one is supposed to have about it ("War was really about state's rights"--likely a big part of it for the rank and file, but definitely not true for the leaders). I've no idea how much emotion is invested in the war anymore.
But if the Dixie Stampede is any indication, where one of the pigs in the pig race is named for the iconic Lee, I suspect that there's a fair bit of "it's an ancient war" in the South too. What makes a glamorized Medieval Times-type amusement possible is that nobody deeply cares about the contest.
Aisha came to it as one for whom the themes of the Civil War were not ancient history. She found parts very awkward, sometimes tasteless or tone-deaf, and generally felt out of place. And she's right, of course(*). But I hope her children will be able to say "it's an ancient war." That might be a lot to hope for--maybe I should say her grandchildren.
The alternative to "it's an ancient war" is that new wars refer to the old in their laundry list of grievances. (Not that the old grievances matter as much as the new, but you want to show continuity in the villainy of your enemies.) That's not the road I want us going down.
(*) Although sometimes ... She complained that the "southerners" door label was light tan and the "northerners" was dark blue; this was tone-deaf. Um. If it had been reversed, would that have been better? I'd have thought the colors were a reference to the uniforms, not demography.