The Greenbrier Co branch are from Thomas' son Archibald. Summers and William in Nicholas Co are sons of Thomas; Basil and Duke are grandchildren through John R. The Webster Co group are from son Thomas Lewis.
Thomas D was a son of Lewis Rigsby of Chatham / Wilkes / Surry Co NC. Most genealogies say that Lewis was a son of William Rigsby of Surry Co. This is probably right, but I don't yet know for sure. I have more information on Lewis and William on my web site.
If you have any additional information on Thomas' descendants I'd like to hear from you. You can either reply here or use the email link on my web pages.