The United States allowed more legal immigrants from 1991 to 2000, between ten and eleven million, than in any previous decade. By comparison, the highest previous decade was the 1900s, when 8.8 million people arrived, increasing the total US population by one percent every year. Specifically, nearly 15% of Americans were foreign-born in 1910, while in 1999, only about 10% were foreign-born.

Immigrants accounted for 4.7 percent of the US population in 1970 and it rose to 6.2 percent in 1980, As of 2010, a quarter of the residents of the United States under 18 are immigrants or are children of immigrants. According to a recent study by the Pew Hispanic Center, in 2008, eight percent of all babies born in the US belonged to illegal immigrant parents.

Legal Immigration to the US

250,000 in the 1930s

2.5 million in the 1950s

4.5 million in the 1970s

7.3 million in the 1980s

10 million in the 1990s

Since 2000, legal immigrants to the US number approximately 1,000,000 per year, of whom about 600,000 who already are in the US change their status. Legal immigrants to the US now are at their highest level ever, at just over 37,000,000. Illegal immigration may account to 1,500,000 per year with at least 700,000 illegal immigrants arriving every year. From 1990 to 2000, immigration led to a 57.4% increase in foreign born population.

Immigration Estimates for the Future

The Census Bureau further estimates the US population will grow from 281 million in 2000 to 397 million in 2050 with immigration, but only to 328 million with no immigration. Additionally, a new report from the Pew Research Center projects that by 2050, 47% of the population will consist of non-Hispanic whites, down from the 2005 figure of 67%. In 1960, there were 85% non-Hispanic whites. The report also foresees the Hispanic population rising from 14% in 2005 to 29% by 2050. Whereas the Asian population is expected to more than triple by 2050. Overall, the population of the US is due to rise from 296 million in 2005 to 438 million in 2050, with 82% of the increase because of immigrants.

In 35 of Americas 50 largest cities, non-Hispanic whites were at the last census or are predicted to be in the minority. In California alone, non-Hispanic whites who were 80% of the state's population in 1970 came down to 42.3% in 2008.

Immigrants mostly settle in seven states, California, New York, Florida, Texas, Pennsylvania, New Jersey and Illinois, that comprises about 44% of the US population on the whole. The combined total population of immigrants in these seven states is 70% of the total foreign-born population as of 2000. If the present birth rate and immigration rate is to remain the same for another 70 to 80 years, the US population would double to a staggering 600 million approximately. The Census Bureau's estimates predict that there will be one billion Americans in 2100, compared to one million people in 1700 and 5.2 million in 1800.