Note: This issue brief was updated on December 19, 2014 to correct a reference that Mecklenburg County, NC, is home to Charlotte.
The U.S. Census Bureau projects that net international migration to the United States will become the primary
driver of the nation’s population growth between 2027 and 2038.1 This brief examines current population
trends among the foreign- and native-born at the county level, and highlights the role that immigrants play in
contributing to population growth and slowing population loss. This analysis does not examine the merits of
population change, but instead focuses on where it is occurring geographically. The Pew Charitable Trusts takes
no position on federal, state, local laws or policies related to immigration.
Over the past 25 years, the total immigrant population has increased and spread across the country. In 1990, the
foreign-born population was 19.7 million or 7.9 percent of the U.S. total, with nearly 3 out of 4 immigrants (73
percent) living in either California, Florida, Illinois, New Jersey, New York, or Texas.2 By 2010, approximately 40
million immigrants made up 13 percent of the overall population, and the proportion of immigrants residing in the
six leading states dropped to 65 percent.3 Over that same time, other states including Nevada, North Carolina,
and Washington experienced large growth in their foreign-born populations.4
An examination of county-level demographic data reveals how immigrants affected population change in specific
regions of the country between 1990 and 2012. While the native- and foreign-born populations both grew across
most of the United States during that period, there are some areas where the native-born population decreased.
This brief illustrates how, in some places, an influx of foreign-born individuals slowed overall population loss
and even reversed it. This is consistent with past research that has found that immigration continues to shape
the country’s demography, particularly in newer immigrant destinations. The Chicago Council on Global
Affairs has shown that immigration has mitigated population loss in the Midwest at the state level5 and in
metropolitan areas.6 Researchers reported in the journal Rural Sociology that immigrants reduced population loss
in nonmetropolitan counties during the 1990s.7 This brief updates and expands on previous research by providing
a county-level analysis of the entire nation over two decades and presenting the demographic context for future
research on the impact of immigration on state and local economies and budgets.
We find four key trends.
- Immigrants have moved beyond traditional gateways. Map 1 illustrates how growth in the foreign-born
population has extended beyond traditional gateways—such as California, Florida, Illinois, New Jersey, New
York, and Texas—into other areas of the United States, especially the Southeast and the Pacific Northwest.
- Native-born population has declined in Middle America. Map 2 shows that while the foreign-born population
was increasing and dispersing, the native-born population was declining in certain areas of the country. This
trend is most strongly observed in the middle of the United States.
- Immigration has driven population growth in the Sun Belt, Pacific Northwest, and Mountain States. Map 3
shows areas where the overall population has increased and how the foreign-born population has contributed
to that growth. Increases in the number of immigrants have driven overall growth in many counties,
particularly in the South and West.
- Immigration has slowed population declines in Middle America. Map 4 illustrates the changes in foreign- and
native-born populations and highlights areas where the growth of the foreign-born population has slowed
overall decline and sometimes has overcome native-born losses for a net population gain.
This information is relevant for a number of reasons. In addition to having the potential to offset population
decline in some areas of the country, immigrants can also compensate for the aging of the native-born
population. The median age of the total U.S. population is rising,8 and the ratio of seniors (ages 65+) to working
age people (ages 25-64) is increasing.9 Immigration mitigates these trends by adding working age adults to the
U.S. population. Nearly half of immigrants admitted between 2003 and 2012 were between the ages of 20 and
40, while only 5 percent were ages 65 or older.10
The size and makeup of the U.S. population has important implications for economic productivity, taxation,
and spending. Immigrants are already disproportionately represented in the labor force with a share of about
16 percent,11 while they make up about 13 percent of the overall population.12 The Pew Research Center has
determined that if current immigration trends and birth rates continue, by 2050 virtually all (93 percent) of the
nation’s working age population growth will come from immigrants and their U.S.-born children.13
Key Terms Used in This Brief
Foreign born: An individual who was not a U.S. citizen at birth or who was born outside the United States,
Puerto Rico, or other U.S. territories and whose parents are not U.S. citizens. The terms “foreign born” and
“immigrant” are used interchangeably throughout this brief.
Native born: Those who are U.S. citizens at birth, namely people born in the United States, Puerto Rico, or
other U.S. territories and those born abroad to at least one parent who is a U.S. citizen.
Total population: Throughout this brief, “total” or “overall” population refers to the adult population 18
years and older.
From 1990 to 2012, the U.S. foreign-born population ages 18 or older increased by 19.3 million or 109 percent—
from 17.7 million in 1990 to 37 million in 2012.14
Map 1 looks at counties and highlights those that have experienced an increase in the proportion of immigrants
between 1990 and 2012. The darker the green, the larger the increase in the foreign-born proportion of the
county’s population. The white areas are counties where the foreign-born population decreased between 1990
and 2012. It should be noted that the immigrant population both grew and spread out across the country faster
in the 1990s than in the 2000s.15 This trend over time can be seen in Pew’s “U.S. Immigration: National and
State Trends and Actions Overview,” released in September 2013, which shows state and national change in the
foreign-born population from 1980 to 2010.16 Gray counties were excluded from the analysis because of small
As might be expected, states traditionally receiving immigrants such as California, Florida, New Jersey, and Texas
have a large number of counties that experienced a sizeable increase in the foreign-born population as a percentage
of total population (indicated by areas of dark green). For example, in Florida, the immigrant population grew from
1.5 million in 1990 to 3.4 million in 2012. Miami-Dade County experienced the state’s largest absolute growth in
immigrants; more than 428,000, from 54 percent of the population in 1990 to 62 percent in 2012.
From 1990 to 2012, the U.S. foreign-born population ages 18 or older increased by 19.3 million or 109 percent.
But many states that have not traditionally been associated with immigration also experienced significant growth
of their foreign-born populations. For example, the number in North Carolina grew from about 105,000 in 1990
to 651,000 in 2012. Mecklenburg County, which includes Charlotte, experienced the largest absolute increase in immigrants (102,000) of any county in the state. In 1990, the foreign-born population in Mecklenburg
County was 16,000, representing 4 percent of the county’s total; by 2012, that figure was 17 percent (118,000).
In Washington, another new immigrant destination, the foreign-born population grew from just under 290,000
to 803,000 over the same period. King County, which includes Seattle, experienced the state’s largest absolute
growth, from 127,000 to almost 364,000— from 11 percent of the county’s population to 24 percent. Adams
County in central Washington experienced the highest percentage increase in the immigrant share of population
in Washington, from 16 percent to 34 percent.
In Colorado, another new immigrant destination, the foreign-born population grew from 129,000 to 441,000. The
northwestern counties of Lake and Garfield experienced the largest increases; Lake County’s foreign-born share
of the population grew from 2 percent to 19 percent, and neighboring Garfield County’s grew from 3 percent in
1990 to 19 percent in 2012. Arapahoe County, just east of Denver, experienced the largest absolute growth in
the foreign-born population in the state, adding 61,000—which represents a 12 percentage point increase in the
share of the population.
In contrast, from 1990 to 2012, immigrants as a share of total county population shrank in the areas that appear
white on Map 1. Notable declines occurred in parts of Maine, western Pennsylvania, West Virginia, eastern Ohio,
and several states along the U.S.-Canada border.
Between 1990 and 2012, the native-born population in the United States
grew from 167 million to 198 million, or approximately 18 percent. But
the view at the county level was more varied. While the native-born
population increased across most counties (indicated by white) the native
population declined in others because of outmigration and a higher death
rate than birth rate. Map 2 highlights counties where the native-born
population decreased between 1990 and 2012. The darker the blue, the
greater the decline in the native-born population. Gray counties were
excluded because of small sample sizes.
As Map 2 shows, the native-born population decreased in the counties
running down the nation’s midsection, and along the Mississippi River
in southern Arkansas and western Mississippi, as well as in some other
isolated areas. Counties in the Great Plains that had relatively small
populations to begin with lost a substantial portion of their native-born
residents. Approximately two-thirds of counties in North Dakota, Kansas,
and Nebraska experienced some decline in their native population; those
counties had an average decline of 12 percent. The native populations
of Motley, Cottle, Hall, and Foard counties in the Texas Panhandle also
experienced a sharp percentage decline: Between 1990 and 2012, the
number of native-born residents in the four counties shrank by 27 percent.
In 1990 the combined population of these counties was just over 7,000,
but by 2012 had dropped to less than 6,000.
The nativeborn population decreased in the counties running down the nation’s midsection, and along the Mississippi River in southern Arkansas and western Mississippi.
In Map 3, all counties in green experienced growth in both foreign- and
native-born populations between 1990 and 2012. Gray counties have
been excluded because of small sample sizes, and counties in white
experienced a decline in the number of either foreign- or native-born
residents, or both. The darker the green, the more the overall population
gain was due to immigration.
Increases in this population played a large role in population growth in
many traditional immigrant-receiving states such as California and New
Jersey, and also helped drive growth in new immigrant destinations in
the Southeast and Mountain States. In California counties where both
populations grew, the foreign-born population accounted for an average
of 43 percent of that increase. Fifty-two of the state’s 58 counties
experienced growth in their foreign- and native-born populations. Los
Angeles County had a net gain of 815,000 immigrants compared with
only 83,000 additional natives. That means the foreign-born population
accounted for 91 percent of the county’s growth from 1990 to 2012.
Several states not traditionally regarded as destinations for immigrants
also saw substantial growth because of immigration, including
Washington, North Carolina, Maryland, and New Mexico. In Maryland,
22 of 24 counties experienced growth in foreign- and native-born
populations, with the former accounting for an average of 24 percent of
growth. Immigration was especially pronounced in Prince George’s County
in the suburbs of Washington, D.C., where the foreign-born population
grew by about 100,000 and the number of native-born residents grew
by less than 9,000. Immigrants accounted for 92 percent of the county’s
growth from 1990 to 2012.
Map 4 highlights the counties where the foreign- and native-born
populations changed either in similar or opposite directions. The green
areas indicate counties where the immigrant population grew and the
native population declined between 1990 and 2012. The blue areas
indicate counties where the number of natives increased and the foreignborn
population declined during this same period. The white areas indicate
counties in which both the native- and foreign-born populations increased
(see Map 3 for more detail), while the tan areas indicate the counties
where the native- and foreign-born both decreased.
In a swath of counties running down the middle of the country, the native population declined while the foreign-born increased.
Growth of both groups between 1990 and 2012 was most common
in counties in the Southeast and the Southwest, while decline in both
populations was most common in counties in the Upper Midwest. Map
4 highlights one trend in particular: In a swath of counties running from
the Dakotas to the Texas Panhandle, and in the southeastern corner of
Arkansas, the native population declined while the foreign-born increased.
In the counties indicated by light green, the growth of the foreign-born did
not fully replace native-born loss, but the population would have declined
even more if not for the growth of the immigrant population. In the dark
green counties, the overall population increased because the growth of
immigrants more than made up for native-born loss, a trend that is seen in
the middle of the country and other parts of the Midwest.
Understanding the impact of immigration on demographic change is vital to analyzing the economic and fiscal
effect immigrants have on states and localities. This brief provides an overview of how changes in the native- and
foreign-born populations have interacted to create distinct patterns in many areas of the country.
In most counties across the nation the native- and foreign-born populations increased between 1990 and 2012,
resulting in overall growth. In a very small number of counties, both groups declined. Most notably, in a large
area of the center of the United States, many counties experienced native-born population loss and foreign-born
gain. Many of these counties still experienced an overall loss of people, but the population would have declined
even more if not for an influx of immigrants. This analysis provides necessary context for further research into the
economic and fiscal effects of these demographic changes.
Data Sources. For data on the foreign- and native-born populations in 1990 we used the decennial census.17 For
data on these populations in 2012, we used estimates from the 2008-2012 American Community Survey, which
is the most recent data available at the time the analysis was conducted.18
Focus on adult population. In order to focus on the impact of immigration on population change, the under-18
population is excluded from the populations of both time periods. Children of immigrants in this country are born
as U.S. citizens and counted in the native-born category, thus contributing to native-born population change.
Excluding those under 18 years old made it possible to avoid overestimating the effect on native population
growth from the native-born children of immigrants. All children born to immigrants after 1990 who had reached
age 18 by 2012 are included in the estimated adult native-born population in the 2008-2012 data. For this reason,
the adult native population in 2008-2012 may be slightly higher because it likely includes these children of
immigrants. Eliminating the under-18 population from the data at both ends of the timeframe greatly reduced this
As a result, the maps largely reflect net change of the foreign-born population due to international migration,
movement from county to county within the United States, or mortality. Similarly, the change in the native-born
population is primarily due to internal movement, a limited degree of international movement (when natives
return from abroad), and deaths. Limiting the data to the population ages 18 and older greatly minimizes the
degree to which births contribute to population change and emphasizes the effect on population from movement
Margin of error. County populations vary widely from millions to only a few hundred, and estimates are
potentially unreliable whenever sample sizes are small. This can affect calculations of foreign- and native-born
populations and any estimated changes over time. Focusing only on the adult population reduces the sample size
even more. To address these concerns and improve the reliability of our analysis, counties with fewer than 1,000
residents over 18 years of age in 1990 were excluded. These counties accounted for less than 1.5 percent of the
Drawing conclusions about any specific county from these data is discouraged. Evaluated nationally, however, the
county data demonstrate regional trends, and the clustering of multiple counties with similar outcomes strongly
suggests underlying patterns.
The immigration and the states project team would like to thank Audrey Singer, a senior fellow at the Brookings
Metropolitan Policy Program, and Rob Paral, principal of Rob Paral and Associates, for their assistance with this
brief. Although they have reviewed it, neither they nor their organizations necessarily endorse its findings or
- U.S. Census Bureau, “International Migration is Projected to Become Primary Driver of U.S. Population Growth for First Time in Nearly Two Centuries,” press release (2013), accessed July 30, 2014, http://www.census.gov/newsroom/press-releases/2013/cb13-89.html.
- The Pew Charitable Trusts, “U.S. Immigration: National and State Trends and Actions” (November 2013), http://www.pewtrusts.org/en/multimedia/data-visualizations/2013/national-and-state-trends-and-actions-overview.
- Rob Paral and Associates, Native and Immigrant Population Change 2000-2008, “US Economic Competitiveness at Risk: A Midwest Call to Action on Immigration Reform,” report of an Independent Task Force, The Chicago Council on Global Affairs (2013), 26, http://www.thechicagocouncil.org/sites/default/files/2013_ImmigrationTaskForce_Final.pdf.
- Rob Paral, “Growing the Heartland: How Immigrants Offset Population Decline and an Aging Workforce in Midwest Metropolitan Areas,” The Chicago Council on Global Affairs, June 2014, http://www.thechicagocouncil.org/sites/default/files/GrowingHeartland_June2014.pdf.
- Katharine M. Donato et al., “Recent Immigrant Settlement in the Nonmetropolitan United States: Evidence From Internal Census Data,” Rural Sociology 72, no. 4 (2007), 538, http://www.actionresearch.illinois.edu/courses/FAA391_Spring12/Donato_2007.pdf.
- Dowell Myers, “The Contribution of Immigration to Reducing Aging in America: Application of the Senior Ratio to Census Projections,” Public Policy & Aging Report 22, no. 2 (Spring 2012), 3, http://ppar.oxfordjournals.org/content/22/2/1.2.full.pdf+html.
- Ibid., 5.
- Bipartisan Policy Center, “Immigration: America’s Demographic Edge,” Immigration Task Force, Staff Paper, (Jan. 2014), 7-8, http://bipartisanpolicy.org/sites/default/files/ImmigrationDemographic.pdf.
- Bureau of Labor Statistics, U.S. Department of Labor, News Release: “Foreign-Born Workers: Labor Force Characteristics, 2013” (May 22, 2012), 2, http://www.bls.gov/news.release/archives/forbrn_05222013.pdf.
- U.S. Census Bureau, American Community Survey. Selected Social Characteristics in the United States, 2012 1-Year Estimates (DP02), http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?src=bkmk.
- Pew Research Center, “Second-Generation Americans: A Portrait of the Adult Children of Immigrants.” Social & Demographic Trends (Feb. 7, 2013), 2, http://www.pewsocialtrends.org/files/2013/02/FINAL_immigrant_generations_report_2-7-13.pdf.
- American Community Survey 2008-2012: 5-Year Estimates, “Sex by Age by Nativity and Citizenship Status” (B05003), http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?src=bkmk; U.S. Census Bureau, Population Division, Ethnic and Hispanic Branch, “1990 Age, Nativity, and Citizenship for the United States, States and Counties CPH-L-114,” 1990 Special Tabulations, accessed Feb. 24, 2014, http://www2.census.gov/prod2/decennial/documents/1990/CPH-L-114.pdf.
- The Pew Charitable Trusts, “U.S. Immigration.”
- U.S. Census Bureau, Population Division, Ethnic and Hispanic Branch, “1990 Age, Nativity, and Citizenship.”
- American Community Survey 2008-2012: 5-Year Estimates, “Sex by Age by Nativity and Citizenship Status.”
- In 1990, there were 3,142 counties and county equivalents. By 2012, the borders changed in the following four counties such that calculations of population change across time were not possible: Prince of Wales-Outer Ketchikan, Skagway-Yakutat-Angoon, and Wrangell-Petersburg in Alaska and Yellowstone National Park, Montana. Virginia is home to independent cities that function as counties, and they are identified as counties in this report. However, the two independent cities of South Boston and Clifton Forge were subsumed into neighboring counties in 1995 and 2001, respectively. To make 1990 and 2008-2012 data comparable, 1990 residents of South Boston were added to Halifax County and those of Clifton Forge to Alleghany County. Lastly, some territory from the Colorado counties of Adam, Boulder, Jefferson, and Weld were reapportioned in 2001 to create Broomfield County. However, even with this change, these four counties’ foreign- and native-born populations grew from 1990 to 2008-2012. Broomfield County was not included in our analysis because it did not exist in 1990. Similarly, Denali Borough, Alaska, was not included as it was incorporated in 1990 and not accounted for in the 1990 decennial census.