I want to offer some products with free shipping but only for customers in USA

I want to offer some products with the free shipping option but only for customers in the United States.

How do I set up my cart so that customers in the US see that a particular item is shipped free but those in other countries see the shipping charges?

Thank you.

Hi, Linda:

I don't know how to reach you so I am trying this approach. There must be an easier way.

I posted this message under General Questions last week. So far 93 views but zero replies. I need your help.

HERE'S THE QUESTION:
I want to offer some products with the free shipping option but only for customers in the United States.

How do I set up my cart so that customers in the US see that a particular item is shipped free but those in other countries see the shipping charges?

Thank you.
Rick

"Remember Captain, a chain is no stronger than its weakest link.
Richard Loo to Dana Andrews in the Purple Heart (1944)