Your William was the son of James H. Chamblee/Hannah Luizah murphree. Here he is in the 1850 census:
1850 census, Blount Co AL p. 125
68/68
James M. Chamblee 28 farmer $890 b. AL
Hannah 28
Robert 10
Mary 5
Phebe 3
Rhoda 2
William H. 1/12
(see other enumerations)
Records are wide open on these families.

The line goes back three more generations to Wake Co NC. William Frank Chamblee's grandfather, Robert Carter Chamblee migrated from Wake Co to the Blount Co area around 1830.