I have now been to look at naturalization petitions and certificates at both the
National Archives (for petitions filed in Southern and Eastern District of New
York -- the federal courts) and at the Kings County clerks office (for petitions
filed in state court in Brooklyn).
The two experiences were very different. The National Archives are air
conditioned, the records are well-kept, and the archivists are very helpful. The
only downside is that it takes a lot of time to request the records and get them.
In contrast, the clerk's office is self-service (they send you to the back and
leave you to your own devices), the records are poorly kept and many of the books
are falling apart, and it is very hot. I have great concerns that the reason why
the files are so badly kept is because "genealogists" who go to look at the files
are not handling these approx. 100 year old documents properly.
I highly recommend that you go and look at these files. The records list where
people were born in Europe, when they were born, what ship they came over on
(particularly important if the name your family now uses is different than the
name on the Ellis Island ship manifests), names of children, addresses. There is
a ton of information. Plus you get to see documents signed by your grandparents
and greatgrandparents. However, please handle these records with care. They are
Good luck with your own searches.