Here's a map of the most popular surnames in each state:
The eastern side of the country is mostly Smith, Johnson, Williams, Brown and the occasional Jones.
You get to the middle of the country and things change a bit. Up north, you get a bunch of Anderson, as well as Olson and Nelson.
Down south, you get Garcia, Martinez and Chavez.
In my state of California, the top names are entirely Latino: Garcia, Hernandez and Lopez.
That's pretty much it, except Hawaii, where they've got Lee, Wong and Kim.