my ge grandmother was cena-cennie-senieor arcenia maxwell she was born in 1861 reported as garza texas. we know very little about her except that the maxwells were from gatesville tx at coryelle creek. she had a brother bob and a sister pink. My aunt wrote a letter of going to look up robert in gatesville  in te 1920's they reported that Pink was given Indian land but Robert didnt go get his. it was reported they were half indian. I do find a robert and senia maxwell in the census in jack county texas that is close to your roberts age. If I run across more will advise.