John Chastain - Gilmer and Gordon Co GA

I am looking for any help on John Chastain who married Mary ?They appear in the 1840 Census in Gilmer Co., Georgia and then appear in Gordon Co., in 1850.He was born abt 1810 in SC as was Mary.His father was William Chastain a baptist minister from SC.His children were John A., Nancy, Martha Ann, William, Benjamin, Sovinah, Henry, Newman, Squire, Sarah Catherine, Mary and Sally.Any help on John and his father William would be greatly appreciated.