Do you have a copy of the death certificate for your grandmother, Cora Hubbard? It should have the names and birth locations of her parents on it. Do you know when and where she married Sidney? Depending on the forms used, there may be additional info on the marriage application. I would check out the family on the 1900 census. Among other info, it will give month & year born, number of years married, place of birth for individual, plus place of birth for parents on each person in the household. And, number children for mother, and number living at the time of the census. If they stayed in Haleboro, I would check the Red River Co, TX GenWeb site. Some GenWeb sites are putting their cemeteries online. Post your query there, too. See if anyone knows of a county history being published. If it included a biographical sketch on John, it might say where he was from, maybe even name his parents.