>>Washington, DC is not really a state.
>
>I have District of Columbia as a State. That one is correct right?
>
>I also have Washington in the list of States. So, if I understand correctly, that one should be removed. Is that correct? If yes, then, it would bring it down to 51. Thus, I would have a missing State. Can you clarify all this?

It all comes down to definitions. By definition, Washington D.C. is not a state. It is also not a country. By definition Puerto Rico is not a state. It is also not a country.

The problem comes from the fact that you have 2 tables and you've called them 'Countries" and "Provinces". It's a question of what you are trying to achieve with the two tables. If having Puerto Rico in your Countries table achieves your purpose then who cares what the table is called. You're going to run into all sorts of these things. Look at the Turks and Caicos Islands, or St. Pierre and Miquelon. Look at Guam. Look at a map and they appear to be countries of their own (except maybe the Turks and Caicos which look like they belong to Canada), but they really aren't.

If you are going to use your provinces table to tell people that there are 52 states (or 53 if you include Puerto Rico, or 54 if you include Guam), then you have a problem. If you only want to be able to say that DC belongs to the U.S., then you should be ok.