Bradley surname dead end

I have been researching the Bradley family with oldest known ancestor Ransom Amos Bradley, born in Tennessee in 1823, died in Birch Tree, Shannon County, Missouri, 1895.  Believe sibling group included:  William Arthur, b/1814 in North Carolina, Cynthia Christine Bradley Clark Heavins, Susannah Bradley Spencer, Joseph Bradley (may or may not be Joseph Hampton Bradley who married Melinda McCloud), Lucious Bradley and Leonidas Bradley.  Brick wall:  their parents?  I have researched the named parents (LDS, Rootsweb, Ancestry) of William R. Bradley and Mahala Kirkpatrick who came out of Kentucky and find them impossible to unlikely.  Any help out there?

Ransom Amos married Elizabeth Kitchen

William Arthur married her sister, Susan