While there are a lot of theories and rumors floating around the internet about Arthur's fate in Red Dead Redemption 2, the simple answer is no, you cannot find Arthur's body in the game.
Once Arthur dies during the main storyline, the game automatically transitions to playing as John Marston. While you can revisit the locations you previously explored as Arthur, there is no way to find his body, as it is not present in the game world.
This has led to a lot of speculation about what happened to Arthur's remains. Some fans believe that he was buried in an unmarked grave in the hills above Annesburg, while others suggest that he may have been cremated or otherwise disposed of by the gang. There are even rumors that his body was hidden away by a mysterious character known as Gavin's friend, whose identity (if they even exist) remains a mystery.
At the end of the day, though, the fate of Arthur's body is something that is left up to the player's imagination. While it might be disappointing for some fans who wanted closure on his story, it's also an example of the game's commitment to realism and storytelling. Just like in real life, death is not always neat and tidy - sometimes there are loose ends and unanswered questions. In its own way, the ambiguity surrounding Arthur's fate is a testament to the emotional impact he had on players throughout the game.
