This is really evident when you look at the genetic data from places like Ancestry.com and 23andMe. The states with highest percentage British/Irish are all in

This is really evident when you look at the genetic data from places like Ancestry.com and 23andMe. The states with highest percentage British/Irish are all in the South: http://www.sciencedirect.com/science/article/pii/S0002929714004765#fig3 http://www.sciencedirect.com/science/article/pii/S0002929714... http://blogs.ancestry.com/ancestry/2014/04/04/a-genetic-census-of-america/ http://blogs.ancestry.com/ancestry/2014/04/04/a-genetic-cens... http://blog.23andme.com/wp-content/uploads/2014/10/Bryc_ASHG2014_textboxes.pdf http://blog.23andme.com/wp-content/uploads/2014/10/Bryc_ASHG...