How do I enter the state when modifying the address for a new customer? It doesn't exist on the form

My business was recently in a trade show where orders were accepted on paper order forms and people paid the total by check or with Square. Now I have all of the order form hard copies and I am trying to create orders to manually fulfill in Shopify – in some cases, products were sold out at the trade show and still need to be fulfilled and shipped directly to them.

The problem is that almost none of these customers have ever placed an order with me, and so I am creating customer profiles for them manually. In trying to adjust their “default address” I am stuck – nowhere does the U.S. state appear on the form. City and postal code, but no state.

How do I enter a state for a U.S. customer address manually when it doesn’t even exist on the form? It exists for customers who have already placed orders on my web site. But it does not exist when trying to create a new customer profile from my end.