"This Office of Immigration Statistics annual flow report presents information on the number and characteristics of foreign nationals ages 18 years and over who were naturalized in the United States during 2007. Data were obtained from administrative records of U.S. Citizenship and Immigration Services (USCIS) of the Department of Homeland Security. These records consist of information from applications for naturalization." The leading countries of birth of new citizens were Mexico, India, Philippines, China, and Vietnam and the leading current states of residence are California, New York, and Florida. The report also presents historical data so that the reader can discern trends in U.S. naturalization.
United States Department of Homeland Security: http://www.dhs.gov/