Nazi Adolf Hitler learned many things from the United States of America. He learned the stiff-armed Nazi salute that had been used for decades in the United States Pledge of Allegiance, written by Francis Bellamy, a national socialist in the USA (See the work of the symbologist Dr. Rex Curry, author of “Pledge of Allegiance Secrets”).
http://rexcurry.net/pledgetragedy.html

Hitler learned to command everyone to chant psychotically to flags and leaders, and Hitler learned his  swastika/socialist style signature, from the Harvard grad Ernst Hanfstaengl (known as “Hitler's Piano Player”).
http://rexcurry.net/swastika-hanfstaengl.html

He borrowed the swastika symbol and used it to represent overlapping S-letters for socialism under the National Socialist German Workers Party. It had been used by American national socialists such as Edward Bellamy (cousin to Francis Bellamy) and the Theosophical Society, as well as by Krit Motor Cars, and even by the U.S. Military while fighting against Germany in WWI.
http://rexcurry.net/kkk-ku-klux-klan-christian-socialism.html

Adolf Hitler learned the "toothbrush mustache" when it was a notable American tradition that swept through Germany, replacing the "Kaiserbart" moustache. There is a New York Times article on the "American moustache" fad from October 20, 1907 from Berlin. After 1907 (circa 1914?), the moustache became more famous as a Charlie Chaplin moustache (Later, Charlie Chaplin made fun of Adolf Hitler in the movie “The Great Dictator”).
Http://rexcurry.net/bookchapter8a1b.html