By the time we get to the final known son of James Mathews Sr. the estimates for the birth years of his last 2 or 3 sons are almost certainly getting further and further away from their actual dates of birth. We know James had at least one daughter and possibly had another son named John and those have not been taken into account in estimating his known sons having been born one every two years. For lack of any other guide, however, we stay with the "every two years" estimation. At worst though, I place the error, individually, at around +10/-5 years for the birth years I have for Isaac, Charles and Matthew.
Very little is known of Matthew and without question he is the most enigmatic of the known sons of James Mathews Sr. We do know that he was a son of James Mathews Sr. since he is named as such in a Brunswick County, Virginia deed.113 We know that he had a wife named Judith.114 Beyond these two facts we cannot say with certainty that any other reference to a Matthew Mathews in any county's records actually refers to the son of James Mathews Sr.
As mentioned in the sections on his brothers Isaac Sr. and Charles, Matthew received 200 acres via deed of gift from a part of his father's 1728 patent for 950 acres of land in the western part of modern day Brunswick County, Virginia. The deed describes it as such: "James Matthis of Edgecombe County North Carolina to his son Matthew Matthis of Brunswick County", dated 7 April 1743. Five years later on 5 October 1748 Matthew and his wife Judith sold the 200 acres his father had given him to Hugh Lambert. Brunswick deed and will records imply the Lamberts were close associates of the Mathews family.
Where did Matthew go after selling this land? Brunswick records do not show him acquiring any more land. In fact, no records from any county where he or any of his extended family were known to have lived show him EVER acquiring any more land. It is another 14 years before we find another Matthew Mathews in the area around Brunswick County. Whether or not this individual is the son of James Mathews Sr. is unknown. A 1762 Lunenburg County (bordered Brunswick County to the west) deed shows that "John Mathis of Brunswick County" sold "Matthew Mathis of Lunenburg County" 160 acres adjoining John's own land.115 This deed brings up another mystery. Who is this John Mathis/Mathews? He is not believed to be the John Mathews who was married to Lucretia Mathews, daughter of Charles Mathews. Perhaps he is the John who is theorized to have been a son of James Mathews Sr.?
It is possible that Matthew Mathews spent at least some time in North Carolina. Granville Grant records show that a Matthew Matthews was one of the sworn chain carriers on a grant awarded to Francis Mabry on 27 April 1753 in Granville County, North Carolina.116 In North Carolina when Royal patents or Granville Grants were surveyed the surveyor would have either chain carriers or sworn chain carriers assisting him in measuring the borders of a survey. Sworn chain carriers were of legal age (over 21) and took an oath to do their job as the law required. It was quite common for them to be related to the grantee or at the very least a close associate. The surveyor was busy with the compass and needle so you'd certainly want someone you trusted to handle the measurements. Francis Mabry was a son of another Francis Mabry who had been a close neighbor of the Mathews in Virginia as far back as the earliest years of the 1700s. James Mathews Sr. almost certainly knew the elder Francis Mabry as far back as 1702 when both were soldiers in the Charles City County militia. Whether or not this Matthew Mathews from the Granville Grant was the son of James Mathews Sr. is debatable, but it seems to not be out of the realm of possibility that he was given the fact that the Mathews and Mabrys were close neighbors for so many years. The elder Francis Mabry also had a daughter named Judith. While this is an interesting fact I do not claim that she was the Judith to whom Matthew was married. She is named in Francis's will, but after that nothing is known of her. Mabry researchers have been open to the possibility that Francis's daughter may have married Matthew since there is no trace of her after Francis Mabry died.
In addition to the Granville Grant Matthew there is also record of a Matthew Mathews serving in the Granville County militia in the mid-1750s who might be the same person.117 Keep in mind that the families of James Mathews Sr. and his sons lived in the extreme western portion of Edgecombe County in that part that would become Halifax County in 1758. Granville County bordered Edgecombe County (and thus Halifax County after it was formed) on the west so if the Matthew Mathews in Granville County was in fact the son of James Mathews Sr. then he wasn't very far away from the rest of his family.
Discussion of any family of Matthew beyond his first wife Judith gets into the realm of high speculation. There are a lot of "ifs" involved. Lunenburg County court books record the administration of the estate of a Mathew Mathis in 1784.118 Was this the son of James Mathews Sr.? The administrator of the estate was another Matthew Mathews, presumably a son. The earlier will of Philemon Russell reveals that one of his daughters was Martha Mathis.119 Lunenburg County deed records show that this Martha Mathis was married to a Matthew Mathis: was this the son of James Mathews Sr? After the death of the Mathew Mathis above Lunenburg County deed records show that this Martha had a son named Philemon Mathis.120
Whether or not these various records all refer to the same Matthew is debatable as there is not much context to tie them all together under a single individual.