The United States provides a path to citizenship for its newcomers. Unlike other immigration countries, however, the United States does not have policies that ease assimilation or directly promote naturalization such as easily accessible and widely advertised language and civic instruction courses. Immigrants are by and large left on their own when facing legal and financial barriers or seeking instruction to pass the citizenship test. Not surprisingly, thus, we find that immigrants’ attributes such as educational attainment, English language proficiency, and income affect naturalization rates. This paper analyzes whether naturalization rates are also affected by neighborhood characteristics and informal networks for assistance and information. Towards that end, we estimate a binary model of immigrants’ citizenship status specifying the size of the immigrant enclave and its level of assimilation as key explanatory variables. The study uses 2005 ACS data, and focuses on immigrants from the Caribbean islands in the New York area. The results suggest that who they are and where they live has substantial impacts on immigrants’ propensities to have acquired US citizenship. Citizenship is unlikely for recent arrivals, those who do not speak English well, are poorly educated, and have a low income. Moreover, living in a neighborhood with a well assimilated immigrant enclave enhances the chance of acquiring US citizenship. This effect is stronger for highly educated than for poorly educated immigrants and thus misses the more vulnerable segments of the immigrant population.