What states are butterfly knives legal in?

A difficult question answer because of the fact that the statutes of the various states describe them differently and give them different names (e.g.: butterfly knives - gravity knives - balisongs - etc). Your best course of action is to call your local law enforcement agency and simply asked if they are prohibited or not.
Why would a butterfly be a knife

geezer

your a spas

zebra they hgave butterfly knifes you doughnut