Jim-There is a large book co-written by four ancestors of William Jennings, Sr. with a great deal of info on the family and with excellent source data.The book is specifically about the ancestors of Robert B. Jennings, Sr., who was the son of William Jennings, Jr. & Agnes Dickerson.Robert Sr and some of his siblings migrated from VA (Nottoway Co. which was formed from Amelia Co.)to both sides of the Savananh River in GA (Lincoln & Wilkes Co.) & SC (Edgefield Dist. near Aikens, SC). The book, with 850 pages of data on descendants and with pictures, plus another 100 pages of source notes and index of individuals, also has a lengthy discussion of the "lost fortune" and trials involved.William, Sr. is the supposed 4th son of Humprehy Jennens & wife Mary Milward. As for Mary Jane "Polly" Pulliam, thye m. Jan. 24., 1724 in Hanover Co. and it appears that the families lived in close proximity as Wm., Sr and William pulliam together witnessed a deed executed by Christopher Smith to Paterson Pulliam of caroline co., VA.
The name of the book is "Jennings, The Descendants and Ancestors of Robert B. Jennings, Sr and Tabitha Lockhart" Authros are Sarah Hattie Hazel Delgado, Thomas Ernest Jennings, Modelle Rawlins Thurman and Francis Jennings Williams.
This Jennings line is my maternal line.I was able to obtain a copy of the book several years ago from Thomas Jennings, one of the authors who lived in Hillsboro, TX, not too far from me in Dallas.The book was also in the Genealogy section of the Dallas main Library.I have no idea whether the book is still available or not.I will be happy to look up data from it if it can be of help.
I also do some volunteer work for the Phillips DNA Project.Thru the DNA tests I was able to verify my line back to my GGGGG GF who d. 1777 in Brunswick Co and discover many "cuzins" with whom I am working to take the line back further.