It's a federal law. No company that operates outside of a given state can use that state's name in it's title.

In general, the Lanham Act prohibits registration of marks which are "primarily geographically descriptive or deceptively misdescriptive" of the goods or services. The prohibition derives from the common law concept that no one person can obtain an exclusive right to use of a geographic name so as to preclude others from truthfully representing to the public that their goods or services originate from the same place.1 A geographic name tells the public something about the product or the producer about which his competitor also has a right to inform the public. No one entity can secure a monopoly of a term which legitimately may be used by others.2 For that reason, geographic marks or names should be free for all to use to truthfully represent to the public that their good or services originate in a particular locale.

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