I am trying to find the names of my great great grandparents. My great grandparents were Robert John Ott and Margaret Ioda Mankin. The were born in 1857 and 1856 respectfully. There are Otts and Mankins in Rutherford County on the 1850 census, and I have the page numbers, but since they were born after the census, I don't know how to go further. They must have been married in Tennessee and then they moved to Texas in the 1890s. Most of the family on my father's side is now deceased, and they never knew who their great greatparents were on their father's side. Please help.