It is quite an interesting map, though. It makes me want to ask lotsd of questions.

Like, whi is "soda" confined mostly to the north east and (to a less extent) the west - except for a big block in the centre (would that be St Louis? On the Mississipi, I think)?

Why is "pop" only used in the northern half of the country?

And what on earth is the "other" stuck in the middle of the border with Canada?