Hi Damon, I show several Alexander's in and around Panola Co, Texas and Caddo Parish, Louisiana in Census records leading up to your 1910 record. These may be relatives of your Thorton. Living with my ancestor Mary in 1880 is an Althia age 60, John 27, Harriet 15 and Rose 13. They are living in Caddo Parish. Given the proximity to Panola County, these could be relatives of your Thorton.