I believe that protectionist policies are ONLY PART of the reason why we became the strongest nation on earth, NOT the ONLY reason. Just as I believe that TODAY it is ONLY PART of the answer. I refer you to harpseal's list of 13 excellent ideas; ONLY 2 involve protectionism. That's 2 out of 13! See harpseal's profile page.
As a Christian Conservative I am more likely to imply that America's deep religious convictions had more to do with our becoming the strongest nation on earth than any trade policy. However, it cannot be denied that America, once upon a time, took measures to protect it's middle-class, it's workforce and it's small businesses; and that these efforts met with very good results.
Today, many of America's small and mid-sized manufacturers are dying because of a lopsided so-called "free trade" policy that is nothing like free trade. It is unfair trade and our gigantic trade deficit is more evidence of how lopsided it is.
Furniture and textile companies 100 years old cannot compete with the slave wages of the PRC, not to mention the 40% devalued yuan, or China's and India's tariffs.
The PRC has an economic warfare strategy of dumping their goods with the express purpose of driving-out American competition. This was admitted openly by 2 PRC senior officers. It is also rather obvious.
Our own Bush administration admits that the mounting job losses are unacceptable; 2.7 million in manufacturing alone.
Furthermore, in post #22 I list just some of the links that support my reasoning.
http://www.freerepublic.com/focus/f-news/996809/posts?page=22#22