US an imperial nation?

 During the 1900's something huge was washing across the nation bringing new ideas to peoples everyday lives; it was called Imperialism. Imperialism is " the policy of extending a nation's authority by territorial acquisition or by the establishment of economic and political hegemony over other nations."(http://www.thefreedictionary.com/imperialism, by Farlex, 2013) Around 800 years ago, the earliest victims of imperialism were Europeans who fell to Western European imperialism.  A European imperialism example would be Germany and the Nazis during the rage of world war 2. Germany was the cause of exploited labor and they had concentration camp workers work in harsh conditions that were almost unbearable.(http://www.michaelparenti.org/Imperialism101.html, by Michael Parenti, 2005). As of today in the 21'st century, there is no known proof of imperialism still going on in the United States although there are small reports in foreign countries who still believe in the harshness of what went on when their parents were just as young as them.(book-The American Vision Modern Times, Joyce Appleby Ph.D., 2006) (picture-http://upload.wikimedia.org/wikipedia/commons/f/f1/Schurz_Imperialism_Bunco_Doll.jpg)