What do you think happened to Jack?

[BoulderFaceplant]

I have no idea what to think became of Jack after killing Edgar Ross. On one hand, he talked to three different people, two of them family members, before killing him. On the other hand, if that “Red Dead” by J. Marston book in GTAV isn’t just an Easter egg (and by the presence of journals in RDR2 this seems possible), it would suggest that not only did Jack survive, but he was comfortable using the Marston name. 

[_GTAFREAK_]

I would say Jack probably didn't became one famous gunslinger, a "Legend of the West" like his late father... even though he had the skills for that. He probably just became famous for being the "John Marston's son".

Why? Because the wild west was "dying" fast by the time Jack killed Edgar. The west was, supposedly, becoming a lot more civilized and a lot less "wild"... so the era of gunslingers had reached its end.

[universetwisters]

He fought in World War 1 and got hit by a train. RIP Jack Marston

[MCMXCII]

He became an author, as evident by several books that you can find in GTAV with his name on them.

[Copcaller]

He gets drafted for ww1 since he's in shape and good with a gun survives the war goes to college and becomes an author lawyer or whatever

[Corndawg93]

I feel Jack went to track down Charles or Sadie, because be became an assassin for an underground society in the year 1924

[Syrens]

I'd like to think he perhaps found peace afterwards, and realized continuing on that path would end in his destruction, much like his old man.