Does he show up in the 1920 census? Do you know where they settled? Were they married in England or the US? When did either pass and where? Were they Catholic?
Might be far easier to get a death certificate.
If married in the US, you might be able to find a marriage document. If they were Catholic, you can try to determine which Parish and then seek to search their records. If the Parish is closed, you can try the parent Arch Diocese.
Just some thoughts.
Good Luck and God Bless,