I would also recommend the discussion of the Keetoowahs in William G. McLoughlin, "After the Trail of Tears: The Cherokees' Struggle for Sovereignty, 1835-1880" (Chapel Hill: University of North Carolina Press, 1994). This was Prof. McLoughlin's last-published book concerning the Cherokees before he died, and discusses the origin and spread of the Keetoowah Society. He says that by 1861 they controlled both houses of the Cherokee legislature.