I think that Charles Steinmetz invented alternating current for distribution purposes.
Along those lines, we may as well include Thaddeus Kosciuszko -- the Polish immigrant who was hired by George Washington to serve as the head of what would later be known as the U.S. Army Corps of Engineers. Without him, the U.S. probably would have lost the American Revolution.
An absolute travesty! It was he, not Marconi, that invented the radio. Marconi was then awarded the patent and the Noble prize for "his" invention. What a F*@!%$# disgrace. There is also the Tesla coil. Tesla transformed civilization. His greatness is the one thing that the Serbs and the Croats actually agree upon!
John Browning the legendary firearms inventor should also be on the list.