The series was produced by Fred Freiberger, who produced Star Trek (1966), and had many future "Star Trek" regulars appear, including Leonard Nimoy, DeForest Kelley, and James Doohan.
As the series progressed, it was revealed that the hero was a Union Army officer in the western theater of the Civil War, and was an expert card player.
The ring Shenandoah (Robert Horton) wore belonged to his brother Walter, killed during the Civil War.
Shenandoah was one of three people who survived a fort's massacre. It is never explained how he survived.