Eric I have attached a zip file containing the two country selects. The first which was created using eCart wizard and has the correct "US" value. The second was created by using css forms builder on the eCart checkout form. I opened css forms builder selected eCommerce and style then resaved the form. This is where the issue started as css forms builder rewrote the values to "United States" as with all the other countries.
Maybe the issue is with me not knowing exactly how css form builder works. But, I would not expected it to rewrite the values of the form. So the issue has nothing to do with the eCart wizard which works great and everything to with me or css form builder.
Hope this helps.