Digital copies, sometimes called "portable files", are copies of your original documents, family group sheets, notes, pedigree charts, etc.
A Wiki is a website that allows multiple users to create, modify and organize web page content in a collaborative manner. FamilySearch.org and ancestry.com both have wiki's.
Be sure to understand any fees that may be required for copies of any records found.
USCIS (U.S. Citizenship and Immigration Services) was formerly known as INS (Immigration and Naturalization Service). Searching for Immigration and naturalization records is essential in genealogy research. The website which allows patrons to order index searches or record copies is at: CISHistory.Library@dhs.gov. Payment is required for searching the indexes, and then payment again to obtain copies of records located. 20th century records include: Certificate Files (C-Files); Registry Files; Visa Files; Alien Registration and A-Files.
The census records may contain a good clue to when a person obtained citizenship.