The data on immigration to the United States in the 1990s are in. As expected, the numbers recently released by the Census Bureau and the Immigration and Naturalization Service (INS) show that immigration boomed from 1991 through 2000. Yet, there are subtle but significant differences that can be gleaned from the data gathered by the Census Bureau, which reports on the stock of immigrants at any one time, versus information from the INS, which tracks the annual flow of immigrants. Census data highlight an upsurge in immigration during the 1990s. INS data are consistent with this but also show a marked decrease in the second half of the decade compared with the first five years of the 1990s.

Data from Census 2000 reveal that the last 30 years of the twentieth century (1970-2000) produced a remarkable recovery in the immigrant (defined as foreign-born) population of the United States following 60 years of decline (1910-1970). The foreign-born population of the United States as a percentage of the U.S. population peaked at 14.7 percent in 1910. As a result of a series of restrictive immigration laws culminating in the “National Origins Quota Act” of 1924, the figure declined every decade thereafter until reaching its nadir in 1970 at 4.7 percent. In 1965, Congress passed a more liberal immigration law. By the 1970s, the effects of that law and other global economic and political factors began to be reflected in immigrant numbers.

The number of foreign-born people in the United States has more than tripled since 1970, and the proportion of immigrants in the country has gone from slightly less than 1 in 20 to more than 1 in 10. In 2000, the majority of these immigrants (51.7 percent) originated from Latin America and the Caribbean. This last figure confirms that a major historical transition took place in the last third of the twentieth century. During this period, the European-dominated immigration that had characterized the United States since its inception was replaced by an immigration process led by the United States’ southern neighbors and, to a lesser extent, by Asia, which accounted for 26.4 percent of the foreign-born population in 2000.

Census data on language hint at the cultural changes wrought by the immigrant surge. In 2000, 47 million people spoke a language other than English at home. Of these, almost 60 percent, or more than 28 million, spoke Spanish.

Both in absolute numbers and percentage of increase, the 1990s stands as the peak immigration decade, culminating an era of growth in immigration. Data from the INS allow us to look more closely at the decade and detect variations in the flow: More immigrants (9,095,417) entered the United States in the decade 1991-2000 than in any other decade in U.S. history, surpassing the previous record of 8,795,386 established from 1901 to1910.

The INS data also show that the immigration flow peaked in the first five years of the 1990s and dropped off significant thereafter. From 1991 to 1995, 5,230,313 immigrants entered the United States. In contrast, during 1996-2000, the number of immigrants totaled 3,865,104, a 26-percent decrease from the previous five-year period.

What accounts for this pattern? There probably is not a single cause. Immigration figures for the early part of the decade reflect the large number of immigrants and their dependents who legalized their status through the amnesty provisions of the Immigration Control and Reform Act of 1986. As with all immigrants, the INS records amnesty recipients as being admitted to the United States as of the year they attain legal residency, regardless of when they physically entered the country. The time period for dependents of amnesty beneficiaries to legalize their status ended in 1995. In addition, in 1996, the United States adopted some tough new immigration laws, requiring higher levels of income on the part of U.S. residents wishing to sponsor a family member under the family-based provisions of the immigration law.

Will we see a continuing decrease in immigration? The data do not indicate that. Annual immigration in the 1990s bottomed out at around 650,000 in 1997 and 1998, but by 2000, the number rose to nearly 850,000.

What will be the impact of 9-11? The September 2001 terrorist attacks on New York and Washington, D.C. have renewed the immigration debate and given new stimulus to advocates of tighter immigration. They, for the moment, have frozen a trend toward a more liberal and bilateral approach toward immigration, especially from Mexico. The U.S. Congress has passed laws intended to bolster homeland security that will affect the rights of immigrants in the United States. However, there has been no fundamental change in immigration law or policy capable of stopping the large-scale flow of immigrants experienced over the last three decades. Negotiations with Mexico have not been suspended formally; the Bush administration seems to intend to take these up again seriously after the November 2002 election.

Finally, there are powerful economic, political, and demographic reasons for continuing immigration to the United States. Economically, key politically powerful industries in the United States, including agribusiness, information technology, hotels, and restaurants are highly dependent on immigrant workers. Politically, immigration is a key issue for the Hispanic community. More Hispanic citizens are voting regularly and are becoming an increasingly important factor in key electoral college states, including California, Texas, Florida, New York, and Illinois. The “asymmetrical bipartisanship” that characterizes the Hispanic electorate (a majority favors the Democrats but a significant minority favors the Republicans) results in both parties bidding for the Hispanic vote. Demographically, the rapid aging of the population of the United States means fewer workers to support retirees, a trend that is mitigated to some extent by the entry into the labor force of young immigrants. Taken together, these economic, political, and demographic factors make the continuation of substantial immigration a more likely scenario for the foreseeable future than an immigration moratorium or a radical reduction in the flow of immigrants into the United States.