How to ...
Replace your Citizenship and Naturalization papers.
N-565, the Application for Replacement Naturalization/Citizenship Document is used to request citizenship and naturalization papers, including a Declaration of Intention, Naturalization Certificate, Certificate of Citizenship, or Repatriation Certificate, or to apply for a special certificate of naturalization as a U.S. citizen to be recognized by a foreign country.
For more information from the U.S. Citizenship and Immigration Services department, including filing fees and a form that can be downloaded, click on http://www.uscis.gov/n-565.