Marty Meyers asked whether it's possible to find naturalization papers if one knows
the number of a Certificate of Arrival and the date it was issued.
My short answer is no. For people who were seeking citizenship after 1925 and
claimed they arrived after June 29, 1906, certificates of arrival were issued by
the Department of Labor or Department of Justice, and the numbers were transcribed
onto manifests. However, there's no index or other means that can be used to use
the C.O.A. number to find declarations of intention, petitions for naturalization,
naturalization certificates, or anything else. The prefix to the C.O.A. number
identifies the court (I think in Marty's relative's case, the "2" is for the
Southern District of New York) and the accompanying date is when the notation on
the manifest was written, but that's it.
However, when applying to the U.S.C.I.S. for naturalization documents, it's still
useful to include the number, because if the C.O.A. is in the file and the clerk
getting the document is on the ball, they can be sure that they have the "right"
New York, N.Y.