In 2013, 8.6 million U.S. residents were eligible to naturalize, according to a report from the Center for Migration Studies of New York. The report, which uses data collected in the U.S. Census Bureau’s American Community Survey, provides detailed estimates of the eligible-to-naturalize in an effort to assist decision-makers in developing strategies to identify and assist immigrants to naturalize and to overcome barriers to naturalization eligibility. Mexican nationals constituted the largest naturalization-eligible population at 2.7 million.