It's inevitable that we carve up geography to group people. Political borders are usually the result of negotiations between land-hungry powers, or politicians seeking to tweak group distribution.
Julian Oliver's Border Bumping project has me thinking again about alternate motivations, so I've assembled some of my favorite alternative approaches to US cultural cartography:
William C. Reynold's slavery map was one of the first artifacts that piqued my schoolboy interest in cartography. It may be quite simplistic, but was (and remains) very effective in communicating the state of the nation in 1856.
Also using communication, MIT, AT&T, IBM, and probably some other TLAs have mapped socially connected regions based on mobile phone calls. Then with Vincent Blondel (of phone identification fame) they went meta.
Neil Freeman has drawn fifty states of equal population.
With a midnight mapping of star constellations to Earth's surface, Jim Davenport also finds a Cascadia in Corona Borealis.
Davenport also cleverly uses Voronoi diagrams to define states based on distance from Starbucks.
Jonathan Dowse also uses Voronoi cells, but choses existing state capital cities for the vertices.
Jason Sundram uses Voronoi around each existing state's largest city. He also has capital and centroid models.
Colin Woodard looks to history to inform 11 nations of distinct cultures.