This site uses two sources of data to report on how many immigrants are eligible to naturalize in Napa County, and to estimate the characteristics of those immigrants.

Immigrants Eligible to Naturalize, from U.S. Office of Immigration Statistics

This information, showing a total of 8,841 immigrants who could naturalize in Napa County, are derived from data that were provided by the Office of Immigration Statistics of the U.S. Department of Homeland Security to a group of researchers including Manuel Pastor of the University of Southern California (USC), David Ayon of Loyola Marymount University, Jonathan A. Fox of the University of California at Santa Cruz, Rob Paral and others.  Information derived from the data set has recently been published by the Woodrow Wilson International Center forScholars.  

Staff at USC's Center for the Study of Immigrant Integration (CSII) processed the original OIS data into more usable shape and then refined the OIS data to account for emigration, mortality and derivative citizenship.  Funding for this effort was generously provided by the Carnegie Corporation of New York.

Click here for a description of the data request made to OIS, the processing, and the Center's refinements to the data.

A complete data set of legal permanent residents by period of entry by naturalization status by 39 countries/world regions may be obtained from the Center for the Study of Immigrant Integration.  Please contact Justin Scoggins at CSII.

An interactive map of the national data may be found at

Immigrant Characteristics at the County Level, from the U.S. Census Bureau

The Office of Immigration Statistics data do not include information on the characteristics of immigrants eligible to naturalize, other than their country and world region of origin.  Data on the age, English ability and possible exemption from naturalization testing are highly relevant to any attempts at public education and services directed at those immigrants who might naturalize.  

We proxy the characteristics of the immigrants eligible to naturalize using data on noncitizens from the American Community Survey, an annual survey conducted by the U.S Census Bureau of about one percent of the U.S. population.  We use five-year aggregate survey data for the period 2006-2010 for the state of California for each of the 30 populations reported by the Office of Immigration Statistics.  We obtained the data by downloading Public Use Microdata Sample files.  Key variables used in the procedure included country of origin, citizenship, age, ability to speak English, and years in the U.S.

Immigrant Residential Patterns, by Census Tract, from the U.S. Census Bureau

County-level populations reported by the Office of Immigration Statistics were apportioned to census tracts using tract-level estimates of the foreign born population by country of origin, using aggregate, tract-level tabulations from the 2006-2010 American Community Survey.

A Note on Children

Immigrants under the age of 18 obtain U.S. citizenship by having a U.S. citizen parent, although other rules apply such as the child's exact age, whether the child was adopted, and the parent's place of residence at the child's birth.  Minors under 18 years receive a Certificate of Citizenship. More information is available at U.S. Citizenship and Immigration Services.