We begin with a map overlay of counties in North Carolina. This was created by requesting geographic entity data from the Census Bureau. To do this, I used the Census Reporter API, which greatly simplifies the process of requesting census data.
Documentation of the process is on the charlesreid1.com wiki.
Here is a map of the Outer Banks of North Carolina:
Dare County is a county right on the Atlantic seaboard. Let's break down Dare County into its different sub-levels, specifically, the census tracts that are in Dare County:
Next, we can grab the same kind of census tract information, but do it for multiple counties by using a Javascript array and looping over it:
You can see how all of this works over at on the charlesreid1.com wiki or in the Github repo for A-Shrubbery.