• The 31.1 million immigrants found in the 2000 Census is unparalleled in American history. It is more than triple the 9.6 million in 1970 and more than double the 14.1 million in 1980.
   

• The 11.3 million (or 57 percent) increase, from 19.8 million in 1990 to 31.1 million in 2000, is also without precedent in our history, both numerically and proportionately. Even during the great wave of immigration from 1900 to 1910, the foreign-born population grew by only 3.2 million (or 31 percent), from 10.3 million to 13.5 million.
   

• The immigrant share of the total U.S. population is also growing at a rate heretofore unknown. The foreign-born population grew from 7.9 percent of the total population in 1990 to 11.1 percent in 2000. If current trends continue, the percentage of the population that is foreign-born will surpass the all-time-high, reached in 1890 of 14.8 percent, by the end of this decade.

"The new figures released by the Census Bureau indicate that we are currently in the midst of a huge social experiment. No country has every attempted to incorporate and assimilate 31 million newcomers into its society," said the Center’s director of research Steven A. Camarota. "And the experiment is by no means over. If current policies remain unchanged, at least 13 million legal and illegal immigrants, and probably more, will likely settle in the United States over the next decade."

Center analysis also shows:

• At least 1.3 million legal and illegal immigrants settled in the United States each year on average in the 1990s, again a level of immigration never before seen in U.S. history. We know this because 13.2 million immigrants indicated in the Census that they came to America in the 1990s. The 13.2 million figure is roughly the size of the entire immigrant population in 1910.
   
• Immigration has become the determinate factor in U.S. population growth. The 13.2 million immigrants who arrived in the 1990s account for about 40 percent of U.S. population growth in the 1990s. Moreover, other Census Bureau data indicates that there were roughly 7 million births to immigrant women in the 1990s. Thus new immigration and births to immigrant women accounted for at least 60 percent of U.S. population growth over the last decade.
   
• The new data show that immigration to the United States continues to become less diverse. People from Latin America now account for the majority of the foreign-born population (52 percent in 2000), up from 31 percent in 1980 and 42 percent in 1990.

Immigration has enormous implications for America, creating very real costs and benefits. Although the issue would seem to be of obvious importance, the nation has not had the kind of vigorous and open debate on the subject that is necessary. This is unfortunate because the growth in the immigrant population reflects specific policy choices made by the United States government, both in terms of the number legal immigrants accepted and the level of resources devoted to controlling illegal immigration. Whatever one thinks of current policy, the number released today by the Census Bureau indicate that the nation faces enormous challenges in integrating the tens of millions of immigrants allowed into the country, and those challenges will only grow if current policies are allowed to remain in place.