I have a a Thomas B Dunnevant (Dunnavant) born in 1821 Virginia. He died in Ohio in 1882. Family lore has there is an Native American connection with him. I have never pursued it but with your posting it has caught my interest. Duniphan and Dunnevant are too close to ignore wouldn't you agree?
I have a David Dunnevant in my family lineage who originally came from Virginia and the Native Amercian connection as well. Supposedly that family line came from either VA or NC/SC area. I haven't done much with them. I wonder if there is a connection.