Hello.All I know is that Dempsey Sumner was the brother of John Sumner, and John Sumner's daughter Elizabeth married Elisha Battle.I am sure you have found all of this, by now, however.These are the notes I found on him:
DEMPSEY Sumner, born about 1712 in Virginia, married about 1750, Martha Baker, daughter of_____, who died after 1779. He was a Justice in Chowan County, North Carolina, in 1750. He was appointed vestryman of St. Paul's Church on April 3, 1738, and still held this office in 1740 and was also Church Warden. He was one of the presiding officers of the County Court of Chowan County in 1746 and again in 1750. He represented Chowan County in the House of Commons in 1744-45 and again in 1757-59; was appointed commissioner to adjust currency in 1744. In 1750 he was a member of the Assembly in New Bern and in that same year he was appointed a Justice of the Peace. He died in Gates County in 1779. His will, dated August 11, 1779, probated at the November Court of 1779, can be found in Will Book 2, page 296, Gates County, North Carolina.
Children of Dempsey and Martha (Baker) Sumner were Dempsey Jr., William, Jethro, Edwin, James Baker, Theirsa, Martha (married Capt. James Riddick), Mary (married Dr. Thomas Petti or Peeti), Letitia, Elizabeth (married Jethro Ballard).
One Dempsey Sumner married Martha Arrington in Nash County, North Carolina 6 October 1866. (Williams & Griffin, p. 108).
A Dempsey Sumner witnessed the will of William Parker 27 December 1750 in Chowan County, North Caroline (Grimes, p. 280).
DAR Patriots Index Dempsey Sumner, born 1725, died November __1779, married Martha Baker, continental soldier, North Carolina.
On July 10th, 1750, John Sumner and Dempsey Sumner were appointed Justices of the Peace for Chowan County, North Carolina.
Not sure why the same Dempsey Sumner seems to either have been born in 1712 or 1725.