That many Jews changed their last names at Ellis Island. This was a universal Jewish myth believed by almost all. But after a thorough investigation it turns out it was extremely rare for it to happen. Jews leaving Europe had to show proper paperwork before boarding the ship. These records were used by the Customs officials to record entry to the US. So whatever name was on your paperwork in Europe is what your name was entering America. (Some people changed their name after arriving here but it didnt happen at Ellis Island)
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