Chicago Green Card immigration Lawyers. Naturalization is the physical process of obtaining citizenship in the United States. Therefore, these two terms are closely related and often used simultaneously. If you are applying for citizenship as an immigrant, you will need to complete the naturalization process first. This will entail submitting an application, completing an interview, passing a citizenship test, and taking an Oath of Allegiance to the U.S. If you are seeking citizenship or naturalization in Illinois, call Kurczaba Law Firm and work with the top immigration lawyer in Chicago, IL.