This may be the Capt. John Blackwell who served in the 3rd Virginia Regiment of the Continental Army in the American Revolution. Other family members Lt. Col. John Webb and Lt. James Smith also served in this regiment with Capt. John Blackwell. They also moved to Granville Co. after the war. All pension records of this Capt. John Blackwell were destroyed in a fire and no information is available regarding his family.

The 1790 NC Census lists no John Blackwells living in Granville Co. However, the AIS Census Report for the years 1791-1799 lists a John Blackwell in Granville. We may assume that John relocated between 1791 and 1799. John's father-in-law, John Pomfret, moved to Granville from King William County between 1782 and 1787. On 1 June 1787, in Hanover Co., John Pomfrett "of Granville County, North Carolina" assigned Christopher Tompkins to be his attorney in King William County, Virginia. The witnesses were Ambrose Edwards and John Blackwell. We assume this John Blackwell was Pomfret's son-in-law who was still in Virginia at the time.592