Hardins of TN/AR

I am looking for more information on my grandmother's line. Here is what I have :My grandmother was Mary Frances Cordelia Hardin. She was born 1889 in TN, then they moved to AR.Her father was William Allen Hardin; her mother was Mary Jane Thompson, b.1848.William'sfather and mother were John Hardin and Amy.Mary Jane Thompson's parents were Carroll Thompson, b,1816, and Sallie Cockman, b. 1817. Does anyone have any other information about this family - earlier generations, country of origin? Thanks!