If you design an online contact form, you should never force your user to enter a state, or, even worse, select one of the 50 US states. Not all users live in the USA.
Some users might live in countries that use other systems, like departments in France or counties in Great Britain or canton in Switzerland. Others aren't used to providing the state they live in like Germans, and states are not used as part of an address information.
If you need this information e.g. for invoicing or mailings, you have to implement country-dependant logic.