#Maps of #Surnames » Sociological Images
http://thesocietypages.org/socimages/2011/02/05/maps-of-surnames
the concentration of last names serves as an echo of immigration and settlement patterns. British-origin names tend to dominate across the U.S., unsurprisingly, particularly Smith, Johnson, and Williams. Because slaves were often given the last names of their owners, a significant proportion of individuals with British last names are African American — for instance, African Americans are about 20% of people named Smith.
http://thesocietypages.org/socimages/files/2011/02/new-england.jpg