I watched this on TV when I was 13 or 14 yrs old and was engrossed in it. It left a lasting impression on me. Even to this day, I still think about it. As a kid, I couldn't have told you if the acting was first rate. Evidently it was; I do remember thinking the actors presented it as if the story had happened to them. I also remember being aware that William Shatner was remarkably restrained in this role and thinking how convincing he was.
I can't say this particular movie sparked my interest in American history, but it certainly looms large. Even if the story has been "Hollywood-ized" with the addition of bogus testimony of the camp commandant, the rest of the story is quite true. The sad story of Civil War POW's at Camp Sumter (the actual name of the prison) should be studied by all, not just students of American history. Incidentally, the Andersonville National Historic Site (outside of Richmond, VA) is the only national park that serves as a memorial for ALL American POW's. Because of having seen this movie, I sought out more info about the actual place and actual facts. This doesn't necessarily prove it's a well made movie, but it's the highest compliment I can pay to The Andersonville Trial.
To me, the time invested in watching this movie is worth it.
