If you think that this map is bad, you should read Colin Woodward's book.
Posters on this site could pick apart Albion's Seed or Joel Garreau's Nine Nations of North America at length, but both offer better analysis, more nuance, and more thoroughly researched versions of what Woodward attempts in American Nations.
Question: Should I read Albion's Seed? I have it on my 'to read' list but haven't bought it yet.
As cultural history I found it very engaging, regardless of how far one takes the views that these 'folkways' continue to impact regional differences 2-4 centuries later. I think you'd enjoy it as a fan of the good historical anecdote.