"It was not uncommon for mixed race Virginians and other Southerners to migrate to the North to "pass" as white."
For the same reason, you find quite a few communities like Goinstown, NC clustered along the VA border. NC was poorly administered by the Lords Proprietors, particularly after Carolina was split into North and South, which made it something of a lawless "frontier" much later than any part of VA or SC. This made it a preferred destination for all manner of peoples who were outside of the pale in VA and other areas, due to religion primarily, but that was not the only reason. This comparative wildness was also why so many pirates called the Outer Banks area "home," aside from the roughness of the Atlantic offshore and the ever-changing nature of inlet and shoal there, which made pursuit nearly impossible by anyone who was not intimately familiar with the area.