If you're a U.S. resident, Kraken will not tell you whether they operate in the State you live in. You just have to go ahead and attempt to register; if they don't have licensure in your State, you're S.O.L.
Therefore, dear readers:
A) If you are registered with Kraken in the United States, please make a post in this thread and tell us what State you live in.
B) Others, who have been unable to register with Kraken because Kraken doesn't have licensure in your State, please post that information too.
Now, let's maintain lists of the States Kraken does and does not operate in, and keep them updated.