Nash made the documentary with about $5,000 and the help of friends in the film business.
Among film interviewees, Nash talked to veterans who served in the same infantry division as his grandfather, including Boston resident Edwin "Bud" Waite. The 87-year-old was an infantry soldier who wasn't part of liberating concentration camps, but visited Dachau later. He said he sees value in Nash's film effort.
"I think it's very important because the younger people nowadays, they don't really understand concentration camps back in World War II," Waite said.
Megargee, who will give a lecture before Thursday's screening, said Nash's film opens up a personal window into what the Allies were fighting against in World War II.
"When you can personalize the history, especially for younger kids, it helps to get them interested. It's one thing to talk about tens of thousands of camps. It's another thing to bring it down to the level of one American soldier," he said.