My ex-husband is a Carwile from the Illinois branch which came from Kentucky and originally from Virginia. He is a decendent of Washington Carwile who was the son of James Henry Carwile (b.1822 in VA, d. 1899 in IL). J.H.Carwile had a brother named George Washington Carwile (1830-1899) who had a child named Tidy Carwile. It might be your grandfather's grandfather.
Ancestry.com has an extensive Carwile family tree where I obtained a lot of information on this Carwile branch, going back to the Jacob Carwile in Campbell Cty, VA in 1750's.