Thomas - thank you for the follow up message. Unfortunately, I have already located those census records and the marriage certificate. I am also the person who wrote and posted that story about John Cox being a Mystery Man on Ancestry!! He was my g-grandfather and NONE of the family has been able to discover anything more about him in decades of searching. I have tried all surrounding states in the 1870 and 1880 census records for him with no success. I will try to get a death certificate per your suggestion, but I don't think it will give any pertinent info as his wife also refused to tell the family anything about him while she lived. I wonder what happened - he was only 17 when he showed up in Texas alone!!