He was clerk of Albemarle 1749-1815, Burgess 1756 -58, and of the Conventions of 1774-75, of Buckingham Co.
John Nicholas of Seven Islands was the great-grandtfather of Mrs. Willie Harrison Nicholas, who married Philip Barbour Ambler. Her letters.

Ni7-2-1 Colonel John C Nicholas b about 1750 member of the Buckinghem Co., Va., Committee of Safety, 1775; Burgess 1774; member of the Convention 1775, married Louise Carter
Ni7-2-2 Elizabeth Nicholas
Ni7-2-3 George Nicholas, married Nannie Scott and had issue.
Ni7-2-4 Robert Carter Nicholas married Martha, widow of Daniel Scott
Ni7-2-5 Margaret Nicholas, married ? Rose, had issue: Robert Rose Ni7-2-5-1 viz. (Ni6-4), John Rose Ni7-2-5-2 and others.
(Ni7-2-6) Martha Nicholas, married Edward Scott of Mannintown, had issue: 
Ni7-2-6-1 John Scott (Ni7-2-6-2) Martha Scott married Dr. Royster.
?Ni7-2-?7 possibly here Ann Nicholas married Sp8-3-1-2-1 Allen Beall born 1728 and died before 1776
ysearch.org/AEFK7 shows a daughter, 
?Ni7-2-8 Leannah Nichols b 1750 Pr. William Co. Va. d 1770

m Warrenton King Spiller b 1737 Prince William Co. Va d 1770 Robertson Tn and had Nancy Spiller b 1769 Robertson Tn d 1835 Williamson Ill m Abraham Tippy and had;
John Tippy b 17 Dec. 1992 Davidson Tn d 1850 Williamson Ill m Louis Lois Lee and had
Edwrad H Tippey b 2 Oct 1818 in Ill d Apr 1870