country zone and state

Hi,
Please to tell me how to set up of the desired country to sell.
For example I just want to sell in the USA.
Then I will unpublished others country.
But, do I need to unpublished all the zone and states of the others country??
Because after I unpublished all others country (except the USA
I desired)but
I can see the zone and state of the country is published at the back end.
Thanks!
Jade

Hi
Is it? (To desire For 1 or more countries to sell products)will be:

Step 1: Configuration > System > Zone > Countries then to unpublished the country not want.

Step 2: Configuration > Display > Custom fields > address_state > Zone -- then to select Countries ??

Step 3: Configuration > Display > Custom fields > address_country > Zone -- then to select Countries ??

Any other setting is needed?

Thanks!