Prospered for 200 years? What are you talking about? The US has only recently (last 50 years or so) been truly successful economically. This is largely due to trade with other countries (people and goods). If you can remember back to freshman Econ in college the main idea was "everyone benefits from trade". We may be losing low skills jobs to china but we are getting low prices as a trade of. Don't buy foreign made products if you don't like it.
*It is very difficult to tell where a product is made, that ford you drive was probably made aborad while my toyota was probably made in Georgia.
Noting is that simpel when it comes to eoconomics.
It's not about being against trade, it's just the type we're seeing with third world countries that allows them unfettered access to our markets while they protect theirs. It's recent policy begun in the nineties. No wonder corporations are packing up and moving to them.