Some scenes were filmed on Robert Duvall's estate in Virginia, which was the site of some Civil War skirmishes.
Martin Sheen was in the Washington, D.C. area in early September 2001, filming scenes for The West Wing (1999). He was prepared to take a Tuesday morning flight from Dulles to LAX if Warner Brothers agreed to pay him $1 million to reprise his role of Robert E. Lee from Gettysburg (1993). Because Warner Brothers passed, Sheen was not on Flight 77 the morning of September 11, 2001.
Russell Crowe was the first choice to play Stonewall Jackson. Crowe expressed initial interest but eventually declined, citing a need to return to Australia and take a break from movie making. The role was then offered to Stephen Lang, who was already signed and rehearsing to reprise his Gettysburg: la dernière bataille (1993) character of General George Pickett. Billy Campbell took over the Pickett role.
The majority of the Civil War re-enactors in the movie volunteered to appear without pay. In return, the production company agreed to donate at least $500,000 to preserve a Civil War battlefield.
The MPAA originally gave the film an R-rating for extended battlefield violence and gore. Director Ron Maxwell shortened or cut out the most objectionable scenes to get the film down to a PG-13 rating.
Damon Kirsche: Harry Macarthy, singing "The Bonnie Blue Flag" for the Northern Virginia high command in the U.S.O.-type performance. Macarthy wrote the verses to the tune of "The Irish Jaunting Car," a vaudeville song from his native country. The song was popular enough to become one of the unofficial Confederate national anthems, alongside "Dixie" and "God Save the South".