Do you give credit to others who have helped you with your research–perhaps someone shared information with you, gave you valuable research suggestions, or shared family ephemera with you? It’s the right thing to do and it makes these individuals more likely to help or share with you in the future
Is your ancestor’s obituary or writeup hiding in an ethnic (often in a foreign language), religious, trade, or other “non-typical” newspaper? Obituaries for immigrant ancestors may be more detailed in a local foreign language newspaper, and a notice in a religious or trade periodical may provide information not given in the local newspaper. Local libraries, historical or genealogical societies may be able to provide information about newspapers of this type.
Interpreting US Census enumerations is sometimes easier if one has a list of the questions that were asked during the enumeration. This page on the US Census Bureau website has a list of all questions asked in census records from 1790-2010.
If your immigrant ancestor has a “derivative” citizenship, then what likely happened is that they were a minor when their father naturalized or they became a citizen upon their marriage to a man who was already a citizen.
Naturalization law is complex and slightly confusing, but if your immigrant ancestor indicates in a census or other record that he was naturalized and you cannot find a record of his or her naturalization, consider the possibility that they obtained citizenship status through the father’s naturalization or their marriage.
And naturalization law and procedure has changed over time–make certain you know what the law and procedure was at the time your ancestor was alive and naturalized.
Of course, like everything else…there are exceptions.