ship logs or where they landed. Where else would I look?
ellis island only has records between certain dates.
i think castle garden might have something.
if folk left from Poland then u should try hamburg records. main departure point was germany not Poland.
besides this, new york was not the only port of entry. some might have entered through canada.
However, check the name spelling and all results at ellis island a few months either side of what your best estimate is.
also, try: familysearch