>>8301755Not a documentary, but my absolute favorite Civil War movie would be The Outlaw Josey Wales.
The Ken Burns documentary is pretty well know, but I mostly just read books on the topic. There's also a decent lecture series from The Great Courses. I'd recommend reading about the western theater of the war; t's vastly underappreciated by the general public and had a major impact on the war as a whole, what with the Confederate army relying heavily on the Mississippi for shipping supplies. It's where Grant made a name for himself, and the actions there prove the effectiveness of Winfield Scott's Anaconda Plan, which at its introduction had been highly ridiculed.