I believe that the reference to Bill Williams by General Shelby was made during his description of the Battle of Buckhorn that was fought near the community of St. James in Stone County. Williams and about 50 others were killed by elements of Shelby's cavalry while on its way to Batesville. There is a marker in St. James briefly discussing the encounter .

The only one of the williams clan mentioned in the book that I found who could have been called Bill was William Day Williams. According the book "Civil War Arkansas Beyond Battles and Leaders" he was captured in Conway County and taken to Batesville in captivity. For that reason I believe that the Bill Williams referred to by General Shelby and mentioned on the marker was not part of the Unionist Conway County Williams clan.