In Red Dead Redemption what do you do after John Marston is killed?

Answer 1

At the end, if you mean when John die, you play as his son Jack Marston and you try to achieve all the missing events to complete the game at 100%.

Well yes, but the game isn't over you see the credits. You have to do one of those side jobs (the question marks) you find this one in black water near the graveyard and talk to that man. He tells you to go to Edgar Ross' house, then you talk to his wife and find out he's in Mexico hunting with another man. When you talk to that man he tells you that he's over by the river. You find Edgar Ross, he says a whole bunch of things then you have to beat him in a duel and that's the end of the game. But you could still go back and do the rest of the side jobs, find treasures, and find outfits, etc.

Answer 2

Once you advance to Jack Marston you will be able to find a stranger mission around Blackwater Trainstation, talk to him and it will trigger the ending mission.

Then you are free to roam around and complete other ingame challenges.

Answer 3

Go to your inventory and press the horse deed. He will gallop to the rescue.

Answer 4

shoot them with the saw-off double barrel