My grandfather (Martin Kus) came from southwestern Poland at the turn of the century. He came originally to Chicago and settled in NW Indiana to work for Standard Oil (later AMOCO and now BP-Amoco). He spoke both fluent Polish and German, so the ancestry is questionable but, per my father, is Polish in origin. My father and most of his siblings spoke Polish until he was in the 3rd grade. He attended a Polish Catholic school by the name of St. Adalberts (patron saint of Poland). His mothers maiden name was Ozug or Ozog. The largest concentration of Kus's is in the Chicago area. Kus is generally considered a Polish surname in the Chicago area, but that part of Europe was contested by Poland, Germany and Austria and was one of the reasons that Hitler invaded Poland in the '30's. I would have to ask my sole surviving uncle about where the name is most common (it is most concentrated in a village in southwestern Poland) but I don't know if I can come up with many answers.