The movie "Gettysburg" is based on the novel, "Killer Angels" by Michael Shraa, and the movie "Gods and Generals" is based on the novel, "Gods and Generals" by his son, Jeff Shraa.

The premise of "Gettysburg" and "Killer Angels" is that Col. Joshua Lawrence Chamberlain's 20th Maine regiment held the Union's left flank on Little Round Top on the second day of the battle and was responsible for turning the tide of the battle against the rebels.

Similarly, the move "Gone with the Wind" is based on Margaret Mitchell's novel, "Gone with the Wind."

I'm not familiar with the movie "Andersonville," but I would not expect a strict representation of the facts primarily because it came out of Hollywood, which, as I said earlier, does not let the facts interfere with a good story.