1. Navigate to your Shopify Shipping & Delivery Settings.
2. Click on "Create new profile".
3. Name the shipping profile.
4. Click "Add products".
5. Select the product(s) you would like to add to this shipping profile, then click "Done".
6. Scroll down to the Shipping origins section and click "Create zone".
7. Name the zone.
8. Search "United States".
9. Un-check Territories and other non-States. Click "Done".
10. Select "Add rate".
11. Choose the Rate Name. Click "Done".
Please keep in mind that the normal Shopify shipping rules apply in regard to naming shipping rates. More information from Shopify is available here.
12. Click "Save".
13. Complete. To test, add one of the products to your cart to confirm shipping is working as expected.