In the Biographical of Mississippi, Monroe McClurg's lineage is given as:
Great-grandfather was a Scotchman who came to America prior the War of Revolution, settling in South Carolina. At Abbeville. He has a son, William McClurg b. 1 Dec 1800. grand father of Monroe McClurg.Yancey Crawford McClurg was the father of Monroe.
Of the family's history, according to the Bio.
Some of the older members of the family settled in Pennsylvania, and one of the family, James McClurg, was a delegate from Virginia to the convention which framed the Constitution of the United States, which instrument he declined to sign......
No doubt "The unnamed Scotsman is James McClurg b. bfe 1765, your subject. And No doubt he is a first cousin of Dr. James McClurg of early Richmond, VA if he is 2nd generation of James and Barbara (Vance) McClurg of Stranraer, Scotland. I believe the older family members to which the Bio says are in PA and VA are John McClurg of Chester Co. PA, my gggg-grandfather and Dr. Walter McClurg of Hampton, VA, father of Dr. James McClurg
It must be remembered that John & Walter McClurg had a brother, James McClurg of which we have no record. However, I would consider the Scottish Probate System for naming Children and bekieve from that coupled with what we do know, that a brother James would name his son James after his Father James which is in the case of Dr. Walter McClurg naming his son James under this system.
The other Known brother of Dr. Walter and John McClurg is Thomas.
Can speculate, but this Mississippi Bio nails it down to at least descendants of James & Barbara (Vance) McClurg.
Incidentally, Dr. Walter McClurg's daughter was named Barbara Vance McClurg.
The bottom line on this story is interested researchers try make the documentedconnection. We are half way there.