Population Growth

Immigration is the second largest contributor to U.S. population growth; immigrants’ U.S. born children are the largest. Together immigrants and their U.S. born children account for roughly 75 percent of annual population increase in the U.S. In absolute terms, that’s an additional 2.25 million people each year.

In 2000 the U.S. total population was 281 million people, of which 11 percent were foreign-born (which includes naturalized citizens, resident legal aliens, and resident illegal aliens).1 Just six years later, the population had grown to 300 million, and the proportion of foreign born had risen to 12.5 percent. By 2050 nearly 20 percent of the U.S. population will be foreign born, while the total population will have ballooned to 438 million. That means an additional 67 million foreigners will migrate to the U.S. by 2050.2 Still, foreign born residents are only the second largest contributor to population growth.

Foreign born residents account for a disproportionately large portion of U.S. births. Native-born Americans average roughly 13 births per thousand people; immigrants average roughly 28 births per thousand. 3 As a result, it is estimated that immigrant births account for a larger portion of total U.S. births than do native-born births.



As the graphs demonstrate, high immigrant birth rates and a quickly growing immigrant population are responsible for the vast majority of U.S. population growth. Although immigrants were under ten percent of the U.S. population in the 1990s, they were responsible for 54 percent of the population growth (counting births to immigrants as immigrant births rather than as native births).4 Based on Census Bureau population estimates, we can infer that about 75 percent of population increase since 2000 is attributable to immigrants.

Immigration-Driven Population Growth is Straining Our Environment and Quality of Life.


From 1990 to 2006, the U.S. population grew by 50.5 million people—an unprecedented 20.3 percent increase. In town after town throughout the U.S., communities are finding that population growth is overcrowding schools, clogging roads, swallowing up open space, taxing the environment, and raising the cost of living for all.

Immigrant Sworn In

The key to population stability is arriving at “replacement rate” fertility (a balance between births and deaths) and zero-net immigration (a balance between immigration and emigration). In fact, Americans did achieve replacement rate fertility in the early 1970s. Yet our population hasn’t leveled off, and it isn’t expected to begin to level off. Why? Because our national leaders have accepted extraordinarily high flows of legal and illegal immigration.

Population growth is directly responsible for unsustainable demand for resources. The result is increased pollution, deforestation, waste, habitat destruction, and soil erosion. America’s environmental priorities cannot be reconciled with the additional infrastructure and resources that a growing population demands. America’s sprawling urban areas are encroaching on fragile coastal wetlands and paving over farmland at alarming rates. And if you think your morning commute is bad now, what will it be like with tens of millions of new drivers on the roads?

Where We’re Headed


Today, the U.S. population has reached more than 306 million. The Pew Research Center reports that current immigration trends will push our population to 438 million by 2050. That’s 132 million additional people needing schools, jobs, and housing—as well as water and other natural resources. Take a moment to imagine what your neighborhood, your city, or your drive to work will be like with 40 percent more people and get ready for your housing prices.

Fortunately unsustainable immigration is not a foregone conclusion. If we immediately reduce immigration to a replacement level, the U.S. population will reach 362 million by 2050, and stabilize soon thereafter. That’s 76 million fewer people than the Pew Research Center tells us to expect if current immigration policy persists.

In 1972, a two-year study by a joint presidential-congressional commission with representatives of major corporations, unions, environmental organizations, and urban, ethnic, and women’s groups recommended freezing immigration at its then-current level of about 400,000 a year as part of a national population policy. The commission concluded that it had “looked for, and have not found, any convincing economic argument for continued population growth. The health of our country does not depend on it, nor does the vitality of business nor the welfare of the average person.” 6

Since then, annual legal immigration levels have risen to over one million persons annually today, and illegal immigration is adding an estimated 500,000 foreign residents annually.7

An expanded discussion of immigration’s impact on U.S. population growth including state-by-state data is available in the publication Immigration and U.S. Population Growth.

Updated June 2008


  1. 2000 Current Population Survey, U.S. Census Bureau.
  2. Jeffrey S. Passel and D’Vera Cohn, U.S. Population Projections: 2005-2050, Pew Research Center, February 11, 2008.
  3. American Community Survey, U.S. Bureau of the Census.
  4. National Center for Health Statistics, Annual Reports.
  5. "Projecting the U.S. Population to 2050: Four Immigration Scenarios," FAIR, 2006.
  6. "Commission on Population and the American Future," John D. Rockefeller 3rd, Chairman, March 27, 1972.
  7. Where Do Illegal Immigrants Live?, USLaw.com, March 10, 2007.