Some filming took place at Prairie Grove Battlefield State Park in Arkansas. The film crew built a false side onto a historic building there, then blew it off for a special effect, assuring the State park officials that no harm would come to the building. The explosion was larger than promised, damaging the historic house's structure.
One of Gregory Peck's greatest heroes from childhood was President Abraham Lincoln. Peck was initially concerned about playing him because he was 66, 10 years older than Lincoln was when he was assassinated.
No actor plays Jefferson Davis, nor is he even mentioned.