Can anyone tell me what movie I was watching?

I was watching a movie that interested me. But all I remember is that it was in black and white, and the main character's name was John Carlton I think, and he had a friend named Sunshine. It was about he and his wife moving from England to the United States during the 1800's and they settled in the west, and a gang of bandits came to their house while John was away getting supplies with Sunshine, the bandits came and threatened the couples baby, they were going to kill the baby if John's wife would not feed them. She fed them and the bandits stole all of their cattle. When John and Sunshine return home they cross the bandits on their way, and John eventually kills the bandits brother and 2 other men. The bandit must be avenged so he comes to John's house with about 20 or 30 other men, and they have a gunfight. The baby then dies because of traumatic shock, and John eventually becomes governor of California, and the movie ends with the couple leaving a party, at their old age, right after John's other love affair catches on to him, the couple leave the party together, and that's the end. Does anyone know what movie that was?