Other
Us Citizenship: u.s. Immigration Made Easy
Gives up-to-date information on immigration. Guides you through the process of becoming a U.S. Citizen, allows you to take a practice test, find out the cost, and even file your application online.
Other
Us citizenship.info: Us Citizenship Library: Dual Citizenship
An in-depth resource that discusses the basic concept of multiple citizenship and gives examples of how one can obtain it. Provides a link to an extensive library of information in an easy to understand question/answer format.
US Department of State
U.s. Department of State: Dual Nationality
The U.S. Department of State provides a brief summary of the concept of dual nationality as defined by the United States government.