In assessing these four quantifiable indices of assimilation, we have chosen to rely on the 1990 U.S. census. Although conducted nine years ago, the decennial census is still the most reliable source of data on these indices. It is based on a large sample, which allows us to extract data on individual immigrant groups with great confidence. For intermarriage data, we also use the June 1994 Current Population Survey, which tracks generational differences. For the most recent totals of the numbers of immigrants and where they reside in the United States, we rely exclusively on the 1998 Current Population Survey.
Citizenship is the most symbolic sign of attachment to the United States.
Not surprisingly, studies have shown that naturalized citizens tend to have a positive outlook on the United States. Once naturalized, immigrants also take on a more active role in the civic life of the country. The longer immigrants reside in the United States, the more likely they are to become U.S. citizens. In the past few years, political conditions in the United States have effected a change in attitudes toward naturalization. The anti-immigrant campaigns in California and in Congress in the middle and late 1990s have been partly responsible for the largest rush to naturalization in the history of the United States.