It included interviews by Frye with actors who appeared in the film and historians, writers and producers of other Civil War books and documentaries. Clips of the movie were shown to illustrate remarks by the guests.
The night's special guest was Robert E. Lee V, great-great-grandson of the Confederate general. Lee, a graduate of St. James Academy in Fairplay, teaches at a private school in Northern Virginia and lives in Maryland.
Having such a famous ancestor is "awesome, but I don't think about it very much except at events like tonight," Lee said.
The film was based on Michael Shaara's Pulitizer-prize winning novel "The Killer Angels." Shaara died in 1988 and didn't live to see the legacy left by his book and the movie, said his son, Jeff Shaara.
He said his family visited Gettysburg when he was 14 years old. His father was a writer, but never had a particular interest in history, he said.
"There was something about that ground, something magical that my father became obsessed with. He had to put those characters on paper. It took him seven years to write it," Shaara said.
The book was rejected by 15 publishers before it was accepted by a small publishing company in 1974. It was right after the Vietnam War ended, a time when military books weren't selling, Shaara said.
Jeff Shaara wrote "Gods and Generals," about events leading up to "The Killer Angels," and is writing the last of the trilogy, a sequel to his father's book.
He said his father's favorite part in the book centered on Sgt. Buster Kilrain, its only fictitious character. Kevin Conway played Kilrain in the movie.
"Few roles have had the meaning of this one for me," Conway said. "I couldn't wait to get to the set in the morning. Those re-enactors made `Gettysburg.' They created reality for the actors who were in the movie. They showed us what it really must have been like."