The proportion of all legal foreign-born residents who have become naturalized U.S. citizens rose to 52% in 2005, the highest level in a quarter of a century and a 14 percentage point increase since 1990, according to an analysis by the Pew Hispanic Center.
The population of naturalized citizens reached 12.8 million in 2005, a historic high that reflects both a rise in the number of legal migrants and an increased likelihood that those who are eligible apply for citizenship. As a result of these combined trends, the average number of naturalizations annually has increased from fewer than 150,000 in the 1970s to more than 650,000 since the mid-1990s.
By 2005 (the last year for which figures are available), naturalized citizens accounted for slightly more than one-in-two (52%) legal foreign-born residents. Among all 36 million foreign-born residents in 2005, naturalized citizens made up a slim plurality (35%) over legal non-citizens (33%) and unauthorized migrants (31%). In 1995, legal non-citizens had accounted for a near majority (47%) of the 24 million foreign-born residents who were in the country at the time, compared to 30% who were naturalized residents and 20% who were unauthorized migrants.
The population of immigrants who are eligible for naturalization was 8.5 million in 2005 and of these more than a third, or nearly 3 million, were Mexican. Mexicans still have a comparatively lower tendency to become U.S. citizens, but the number of naturalized citizens from Mexico rose by 144% from 1995 to 2005--the most of any major sending country.