If you're talking about the Civil War itself, I'd say that's far from true.
If we go all the way back to Gone with the Wind, or Birth of a Nation, it's clear that even liberal Hollywood has bent over backwards to be "fair and balanced" toward Southerners.
Of course, I do watch very few movies, so there might be whole genres out there I don't know about, but can't think of even one recently which matches your description.
Can you name some?
The most recently released Civil War movie was about northern Copperheads who were apparently early civil rights leaders. They were non-racist but anti-war. The bad guys are evil Republican violators of civil rights.
As anybody who knows anything about the Copperheads will attest, this portrayal is ludicrous.
Years earlier there was “The Great Locomotive Chase” and “The Hunley” - neither potentials for the Oscar, but both interesting treatments of their respective subjects, and both respectful of both sides of the war.
If there is a movie that fits Shadowstrike’s prescription I don’t know what it is. Josie Wales stands as the most revisionist treatment I’ve seen (FTR: I still liked the movie in spite of their flight of fancy).