The idea that immigration officers at Ellis Island were a bunch of rent-a-cops scribbling down whatever names struck their fancy falls into the same category as Washington chopping down the cherry tree or the CIA killing Kennedy. Immigration officers at Ellis Island (and its precursor, Castle Garden) were accompanied by interpreters who were required to know at least three languages, while ancillary interpreters with knowledge of more obscure languages circulated to ensure competency—and in this context, Yiddish, German, Russian, and Polish were far from obscure.
None of this even matters, though, because immigration officers at Ellis Island never wrote down immigrants’ names. They obtained those names from ships’ manifests, compiled at the port of origin. Nor is it possible that the same mythic scenario was enacted on the European end. Ships’ manifests were recorded from passports and other travel papers, and the shipping companies were very careful not to make errors, because errors cost them money: inaccuracies were grounds for deporting improperly documented or unqualified people back to Europe at company expense. [link]