In 1772, a relative of mine (Rev William Martin) took five shiploads of Presbyterians to S. Carolina and helped them settle in the northern areas of S. Carolina. In the book, "Scotch-Irish Migration to South Carolina, 1772" I have the name of Captain John Martin, who I believe was a Captain of one of the five ships (Hopewell). I have no record of him getting land at this time. Johns are often called Jack. I have no further information. I have always suspected he was the father of two of my relatives but have been unable to nail that down definatively. Good luck in your search.