I do not know anything on any of his family. His children were told Robert Andrew Lankford (1867-1933) was like 3/4 Indian. He died near McAlester, Ok July 1933. A cousin said he had brothers in the McAlester area, but she could not remember their name.
Humphreys Funeral Home in McAlester, Ok have a Lee Lankford that died in 1925, Minnie Edward 1938, and the infant son of H.H. & Vera Lankford 15 Dec 1919 all of McAlester. I do not know if any or all of them were related to Robert Andrew Lankford or not.