As far as I know there were 5 different people with that name:
John Marston (1576-1634) English poet
John Marston (1795-1885) U.S. Navy Officer
John Marston (1836-1918) English businessman
John Marston (1893-1938) English cricketeer
John Westland Marston (born 1819) English dramatist
Source: Wikipedia
The John Marston from Red Dead Redemption is not real. He is a fictional character. But, some people have that name.
The future ghost of john marston
John Westland Marston died in 1890.
John Marston was born on October 7, 1576.
John Marston was born on October 7, 1576.
John Marston - poet - was born in 1576.
John Westland Marston died in 1890.
John Westland Marston was born in 1819.
John Marston - cricketer - died in 1938.
John Marston - cricketer - was born in 1893.
there is a mission in which you kill the man who kilss John Marston, after this is the credits
The final task after John Marston's death and you take over as Jack Marston is to track down and kill Edgar Ross, the man responsible for John's killing.
Rob Wheithoff is the voice of the main character, John Marston.