Doctor Jennings was the youngest son of Robert "Robin" Jennings of Prince Edward County, Virginia. Doctor was his first name rather than a title. Doctor came to Decatur County from Maury County and settled near Jeanette. He had 3 sons: Wylie who moved on to Texas, Schayler who went to Utah, and Hiram who stayed in Decatur County. Hiram married Eliza Arnold. They were the parents of 10 children: James W. who married Reena "Sis" Barnett first and then Harriet Dodd; Mary H. who married Samuel Madison Houston; John Henry who married Martha Elvira Thomas; Doctor S. who died at the age of 12; Martha A. who married Harvey M. Jordan; Ezra A. who died at the age of 18; Phebe E. who married John Howell; Rhoda C. who married David Burkett; Schuyler who died at the age of 2; William Perry who married Beckey Quinn.