Had the same problem, but I found out I was looking at the wrong place. Sent across the Wild West time and time again to hunt down the enemies of the government, eventually Marston's redemption is complete, and his family is set free after being held hostage by the government. For the most part, most of the Stranger missions in the game can be completed by both John and Jack. Most modern games will alert the player that they are entering into the endgame, but older titles don't always provide this luxury. I completed "women and cattle" and headed on out to gaptooth ridge however that Sam Odessa feller ain't there.
nest...