Cain's Cutthroats (1970)

Following the Civil War, Confederate Captain Justice Cain has retired to a quiet life with his young son and black wife. However, the men of his old outfit, known as Cain's Cutthroats, have turned to lives of murder, torture and robbery. They attempt to convince Cain to ride with them once more. He refuses, and the Cutthroats murder his family. Swearing vengeance, Cain teams up with a colorful preacher/bounty hunter, and hunts down his family's killers one at a time.