Library of Congress, Washington, D.C. has manuscripts, publications and microfilms of a wide range of materials useful to genealogical research. Their website is free and easy to use.
City Directories provide names and occupations of town residents and much local business information.
The Research Log is very important for the time when you share you data or decide to publish your work. You will need to know your sources for obtaining each piece of information. Be VERY specific with your information quoting authors, titles, pages, publishers, etc.
[Sources & Evidence]
A Declaration of Intention is a document an alien usually filed in a court declaring his intention to apply for citizenship after fulfillment of the residency requirement.
Collective naturalization is a process used when a government acquires the territory of a foreign government by treaty or cession, and the inhabitants receive the rights and privileges of citizenship.