This report offers context for consideration of immigration policy options by presenting data on key geographic, demographic, social, and economic characteristics of the foreign-born population residing in the United States. Data on the native-born population are often shown for comparison. The report relies heavily on the 2010 American Community Survey (ACS) Public Use Micro Sample (PUMS), the largest most representative and recent dataset available on the U.S. population. In some instances, other data sources, such as Decennial Census and Current Population Survey data are introduced. At times, the report discusses possible reasons for patterns observed in the data. The term "foreign-born" used in this report refers to people born outside the United States who do not automatically acquire citizenship at birth. The foreign born have a variety of immigration statuses and include immigrants, refugees, nonimmigrants, and persons illegally residing in the United States. This report often distinguishes between two groups of foreign-born individuals: noncitizens (a broad category that includes unauthorized aliens as well as legal permanent residents) and naturalized U.S. citizens. Interest in the U.S. foreign born stems, in part, from the changing demographic profile of the U.S. population, the rapidity of such change, and how both trends correspond to the objectives of U.S. immigration policy. Although relatively small in absolute terms, the foreign born are growing faster than the native-born population generally and specifically among young people and the civilian labor force. Moreover, much policy attention is devoted to dealing with the estimated 11.2 million foreign born (as of 2010) residing illegally in the United States. In 1970, the foreign born numbered 9.7 million people, or 4.8% of the total U.S. population, their lowest proportion since 1850. By 2010, the foreign-born population had increased to 39.9 million people representing 12.9% of the total U.S. population (see Figure 1 ). Although the absolute number of foreign born is higher than at any point in the nation's history, the foreign-born proportion of the total U.S. population was still lower in 2010 than peaks reached at the beginning of the 20 th Century. This report presents information on the foreign-born population that is relevant to several prominent immigration policy issues, including the unauthorized alien population; proposed revisions to current immigration policies; the skill and educational composition of new immigrants; and the impact of foreign-born workers on the U.S. economy. Using the 2010 ACS PUMS, the report describe characteristics of the foreign-born that relate directly to these immigration policy issues. The report begins by placing the current foreign-born population in historical context. It then describes from what regions of the world the foreign born originate, where they settle in the United States, and how these foreign origins and U.S. destinations have changed over the past five decades. Because legal status is central to immigration policy, the report discusses the unauthorized population and naturalization trends and often breaks out descriptive statistics by citizenship status throughout the text. The report describes several critical determinants of labor market outcomes, including age, educational attainment, and English language ability, and then compares the industrial sector and occupational distribution of the foreign born with the native born. Finally, the report presents several measures of economic well-being, including median income and poverty. In 2010, the nation's 39.9 million foreign-born persons represented 12.9% of the total U.S. population ( Figure 1 ). While this proportion remains lower than those reached during the turn of the last century, Figure 1 illustrates that the proportion of the foreign-born population has increased steadily since 1970. Moreover, the foreign-born population's contribution to total population growth in recent years—31.6% between 2000 and 2010—has been disproportionate for its size. The relatively high foreign-born proportion between the late 19 th century and 1920 resulted from several factors, including the U.S. industrial revolution, which generated substantial labor demand; political and economic turmoil throughout Europe during the latter 19 th Century; and the expansion of affordable transatlantic travel. In response to these historically high immigration flows, Congress passed the Immigration Act of 1924, which limited, by country, the number of new immigrants to a proportion of those already living in the United States and reduced immigration levels overall. The Great Depression reduced the foreign-born population by curtailing U.S. labor demand and worldwide migration flows. The Immigration and Nationality Act (INA) of 1952 collected and codified existing immigration law provisions into one organized structure. Amended many times, it remains the foundation of U.S. immigration law. The 1952 Act introduced a system of preferences based on family reunification and skills that upheld and reinforced the national origins quota system established in 1924. In 1965, Congress amended the INA, removing widely perceived discriminatory provisions of previous immigration laws and loosening numerical restrictions on immigration. The 1965 revisions to the INA also had the effect of gradually shifting the ethnic composition of the immigrant flow away from Europe and toward Latin America and Asia. Subsequent legislation—such as the Refugee Act of 1980 ; the Immigration Reform and Control Act of 1986 , which legalized the status of 2.7 million previously unauthorized residents; and the Immigration and Nationality Act Amendments of 1990 —have all increased the number of the foreign born directly by expanding legal immigration to the United States. These laws have also increased the numbers of foreign born indirectly because naturalized immigrants and legal permanent residents can sponsor for citizenship their relatives living abroad. Legislation aside, the U.S. foreign born also expanded from the aftermath of the Vietnam War, Central American political turmoil, greater numbers of U.S.-based foreign-born students and business people, and greater U.S. citizen contact with foreign nationals from international travel, study, and work assignments. Origin countries of the foreign born have changed since 1960 in ways that have increased U.S. population diversity. The absolute number of foreign born by region of birth ( Table 1 ) and the percent distribution of the total foreign-born population by region ( Figure 2 ) illustrate these trends. The proportion of all foreign-born persons originating from Europe declined from 74% in 1960 to 12% by 2010. Over the same period, fivefold increases occurred in the proportion from Latin America (9% to 53%) and Asia (5% to 28%). Proportions from other areas, including Canada, increased and then dropped over this period, although absolute numbers from these areas have increased steadily. The shift in the origins of the foreign born becomes more vivid when examining specific countries. In 1960, European nations represented eight of the top 10 origin countries for the foreign born ( Table 2 ). By 1990, that figure had dropped to three countries, and by 2010, no European country ranked among the top 10 origin countries. In contrast, in 1960 only one country from either Latin America or Asia ranked among the top 10 origin countries (Mexico), but by 2010 all of the top 10 origin countries were from these two regions. Trends on the top 10 origin countries for the foreign-born population reflect not only foreign-born composition but also immigrant diversity, a central principle governing legal immigration policy and the rationale for the Diversity Visa Lottery, which admits 55,000 persons annually from countries sending relatively few immigrants. The geography of foreign-born population settlement in the United States can be divided between the "stock" of the existing population and the "flow" of the recently arrived foreign born. The latter become especially visible during the past two decades in U.S. regions, cities, and rural areas that had not experienced recent foreign-born population growth, prompting some states and localities to pass or consider ordinances addressing immigration-related policy issues. As in previous decades, the foreign born continue to be concentrated in the nation's most populous states ( Table A-3 ). Six states—California, New York, Florida, Texas, New Jersey, and Illinois—accounted for 73%, 68%, and 65% of the entire foreign-born population in 1990, 2000, and 2010, respectively. Nationally, a much smaller proportion of the foreign born (8.5%) are concentrated in rural areas compared to the native born (23.5%). The declining proportion of foreign born living in the most populous six states reflects greater population dispersion to what are referred to as "new immigrant destinations" in both urban and rural areas. The extent of this geographic shift can be seen in Figure 3 , which displays foreign-born population growth for all states between 1990 and 2010. Notably, 10 of the 12 states with the highest foreign-born population growth rates are located in the South and Mountain West, two areas that as recently as 1960 contained 12.5% of the total foreign-born population, a figure that had increased to 38.0% by 2010. States with the lowest foreign-born population growth during this period were concentrated in the Northeast, the northern Midwest, and California. Moreover, many of these same states experienced total population growth that exceeded the national average of 7.0% ( Table A-3 ). The correspondence between foreign-born and total population growth during this period often resulted from, among other factors, growing labor demand in the construction and low-skilled service sectors. Outside of the more established destination states of Texas and Florida, foreign-born population growth in the South and Mountain West represents a considerable demographic shift. Period of arrival data ( Figure 4 ) reflect the large and recent increase in the foreign-born population. In 2010, almost 35% of all foreign-born persons in the United States had arrived since 2000, and almost 62% since 1990. Greater proportions of noncitizens than naturalized citizens arrived this past decade, mirroring to some extent the time required to attain citizenship. Legal status of the foreign born has received increased attention with the growing estimated size of the unauthorized population, the geographic dispersion of the foreign born to new U.S. destinations, and increased border security concerns. Legal status of the foreign born encompasses three broad groups: unauthorized aliens, legal noncitizens (which includes legal permanent and legal temporary residents), and naturalized citizens that are described below. According to the most recent estimates of foreign-born legal status ( Figure 5 ), unauthorized aliens, legal residents (permanent and temporary) and naturalized citizens made up, respectively, 28%, 35% and 37% of the foreign-born population. Applied to the total estimated foreign-born population of 39.9 million persons in 2010 (computed from the ACS data), these percentages yield absolute population sizes of 11.2 million for unauthorized aliens, 14.0 million for legal residents, and 14.8 million for naturalized citizens. Unauthorized aliens are part of the noncitizen foreign-born population captured by the American Community Survey. However, surveys of the population such as the ACS, the CPS and other nationally representative datasets are only permitted to record if respondents are citizens, but not if they are unauthorized aliens. Therefore, policymakers typically rely on estimates produced by government agencies and private organizations to have a sense of how many unauthorized noncitizens live in the United States. In 2010, the unauthorized population was estimated at roughly 11 million persons ( Figure 6 ). Estimates of the unauthorized population in Figure 6 are shown from 1986, the year Congress passed the Immigration Reform and Control Act (IRCA), which legalized 2.7 million unauthorized aliens, through the most recent year for which reliable estimates are available (2010). Some attribute declining incoming flows and estimated unauthorized population sizes after 2007 to the economic downturn and increased enforcement efforts. Some have suggested that greater enforcement of immigration laws likely reduced the overall flow from what it would have been during this period without such action. Legal residents include immigrants and nonimmigrants. Immigrants are synonymous with legal permanent residents (LPRs) and refer to foreign nationals who come to live lawfully and permanently in the United States. Nonimmigrants are admitted for a designated period of time and a specific purpose, and include foreign students, diplomats, temporary agricultural workers, persons on work assignments, and exchange visitors, among others. Conditions for immigrant admission to the United States are more stringent than those for nonimmigrants, yet once admitted, immigrants are subject to few restrictions regarding changes in employment and may apply for U.S. citizenship through the naturalization process, generally after five years. The process of converting legal permanent resident status to U.S. citizenship is referred to as naturalization. In most cases, persons wishing to naturalize must first be permanent residents. Naturalization requires applicants to possess certain eligibility criteria, including a minimum age of 18; permanent residency status for five years (three years in some circumstances); good moral character; basic knowledge of U.S. government; continuous presence in the United States (generally fewer than 6 months abroad during the entire permanent residency status period requirement); and the ability to read, write, and speak basic English. These and other requirements explain the greater rate of naturalization among persons who have lived for more years in the United States ( Table A-2 ). Because citizenship confers the right to vote, naturalization trends may sometimes have political impacts. Over the longer term, however, naturalization trends have demographic implications because citizens are accorded higher preferences than legal permanent residents under U.S. immigration law to sponsor immediate and extended family members to live in the United States . As Figure 7 illustrates, in the past four decades, the total foreign-born and naturalized foreign-born populations have increased consistently while the proportion of foreign born who are naturalized has declined consistently from 63.6% in 1970 to 37.0% in 2010. Figure 8 shows that prime working ages dominate the foreign born, with six of every 10 persons between the ages 25 to 54. By contrast, just four of every 10 native-born persons falls within this age group. Above age 55, the foreign born largely resemble the native born, while among youth, the two populations differ considerably: children under 18 comprise 26% of the native-born population but just 7% of the foreign-born population. Moreover, among the foreign born, the age distribution differs substantially between the generally older naturalized citizen population and younger noncitizen population. The foreign born, 12.9% of the U.S. population, contribute disproportionately to the U.S. population across all age groups ( Table 3 ). Between 2000 and 2010, the foreign born contributed 8.8 million, or almost a third of the entire U.S. population increase of 27.9 million persons. Especially noteworthy was the foreign-born contribution of 5.4 million persons in the 25-54 prime working-age adult group. Some of this change occurred because the native born aged into older age cohorts. The foreign-born contribution to the child-age population was negative during this period, but this negative figure does not reflect a decline in child-bearing among foreign-born adults. Rather it reflects more native-born children born to foreign-born parents (see following discussion and Table 4 ). Among those ages 65 and older, the foreign born contributed just over a quarter (1.5 million persons) of the total U.S. increase (5.5 million persons). Most children of foreign-born parents are born in the United States ( Table 4 ). Of the 16.9 million children with at least one foreign-born parent in 2010, 14.5 million, or 86%, were born in the United States. Children with foreign-born parentage comprised almost one-fourth (24%) of the 70.6 million U.S. children under age 18. Native-born children with foreign-born parents confound the computation of foreign-born median age. Traditionally among the foreign born, noncitizens with less U.S. experience are often young adults with the most to gain economically over their working careers by migrating to a new country. Most foreign born are in fact relatively young, but because their U.S.-born children are included in native-born population figures, the foreign born have a higher median age (40) than the native born (35). However, when median ages are recomputed by reclassifying native-born minor children of foreign-born parents among the 38 million foreign born, the foreign-born median age (32) becomes less than the native-born median age (37). Across several family and household measures, such as marital status (e.g., married, divorced, never married) and household structure (e.g., two-parent households, one-parent households), differences between the native born and foreign born are relatively modest ( Figure 9 ). Figure 10 presents household size—a commonly used measure of household structure—by nativity and citizenship status. Higher proportions of the native-born live in one- or two-person households compared to either foreign born group. Foreign-born noncitizens, by contrast, are found in equal proportions across all five categories shown. Differences in household size by nativity and citizenship status reflect several characteristics. Native-born persons and naturalized citizens, who have higher incomes than noncitizens (see Table 10 ), are more able to afford living alone or in nuclear families, if so preferred, compared to noncitizens who have lower median incomes. Age structure plays a role, particularly among the native born, with young adults and the elderly more likely to live alone. Cultural preferences can also influence living arrangements, with multi-generational households more common among the foreign born. Educational attainment correlates positively with several public policy objectives, including labor market participation, higher incomes, improved health, improved child welfare, reduced public service utilization, and greater civic participation. Average educational attainment is lower for the foreign born than it is for the native born because many of the foreign born lack a high school diploma ( Figure 11 ). However, at the other end of the education distribution, the proportion of the foreign born with at least a bachelor's degree matches that of the native born. Foreign-born naturalized citizens have higher education levels than foreign-born noncitizens. Average education levels have been rising consistently throughout the world, and consequently, more recent immigrants, on average, arrive to the United States with more years of schooling than immigrants who arrived in earlier decades, as illustrated in the period of arrival data in Figure 11 . The proportion of the foreign born with a bachelor's degree has increased by roughly 50% since 1950, and from 22% in that decade to 31% for those arriving this past decade. Figure 11 shows that the educational attainment categories of the foreign born that have declined over the period examined include those who completed high school or some college. However, the figure also shows that the proportion of the foreign born without a high school diploma remained unchanged over this time. While the proportions of foreign born in each of the four broad education categories presented in Figure 11 suggest only modest changes in educational composition over time, they conceal significant increases in average schooling levels occurring in many countries. The foreign born from Mexico, Central America, and the Caribbean have the lowest proportions of college graduates and the highest proportions of persons lacking a high school diploma, in sharp contrast with those from Africa, Eastern Europe, Asia, and the Middle East ( Figure 12 ). Mexico's disproportionately high percentage of persons with less than a high school diploma may be attributable to the large proportion of unauthorized aliens from that country, a group with lower average education levels than other foreign born. Like education, English language ability positively influences labor market outcomes and social and cultural integration in the United States. Characteristics associated with higher education levels are also associated with English language ability, as shown in Table 5 . Research has shown that English language ability tends to improve substantially over time, and second- and third-generation immigrants often lose entirely the native languages of their parents. Such findings are borne out in Table 5 . Youth, who are much more likely to be enrolled in U.S. schools and who acquire languages more easily than adults, have the highest English language facility of all age groups, with nine out of 10 minors reporting that they speak English "well" or "very well." Two-thirds of all foreign-born working-age adults ages 25 to 64 also report similar English language proficiency. As expected, naturalized citizens exhibit stronger English language skills than noncitizens, reflecting U.S. experience. Among origin regions, foreign-born persons from Mexico and Central America report the lowest average English proficiency, while those from Africa, Western Europe, Canada, and Oceania, where English is typically spoken, report the highest. In 2010, the foreign-born population accounted for 25.5 million, or 16.3%, of the total U.S. civilian labor force of 156.0 million. This proportion represents a considerable increase since 2000, when 17.4 million foreign-born persons accounted for 12.4% of the labor force, and mirrors higher foreign-born population growth generally within this age range. Labor force participation rates for foreign-born and native-born workers differ significantly for men and women ( Table 6 ). Foreign-born male workers exhibit consistently higher labor force participation rates than native-born workers both in total and across all age and education categories. In contrast, foreign-born female workers exhibit lower rates than native-born women except at lower education levels. Among all groups, labor force participation increases with education and from ages 16 to 44. Other characteristics among the foreign born significantly affect their labor force participation. As shown in Table A-1 , male naturalized citizens have lower labor force participation rates than male noncitizens. The reverse is true for women, which may reflect greater employment opportunity for those with citizenship, higher education levels, and more U.S. experience. Labor force participation increases during the first 30 years of U.S. experience only slightly for men but substantially for women, before declining significantly as both groups approach retirement. By region, participation is higher for foreign-born men and women from Latin America and Africa and lower for those from Europe, Oceania, and Canada ( Table A-1 ) . Differences between the employment distribution of the native born and foreign born are found among noncitizens. Figures in Table 7 show that naturalized citizens differ little in this respect when compared with the numerically dominant native-born workforce. The noncitizen workforce, however, is more concentrated in agriculture, construction, manufacturing, other services, and accommodation and food services, and less in retail trade, finance, insurance, and real estate, education, health care, and public administration. To some extent, this difference in concentration may mirror skill requirements, with noncitizens more concentrated in industries employing less-skilled workers. Yet in the highly skilled professional, scientific, and management sector, the noncitizen foreign born are slightly more concentrated than either naturalized citizens or the native born. Foreign-born educational attainment and job competition between foreign-born and native-born workers continue to be perennial concerns, particularly during economic recessions. Yet, U.S. dependence on foreign-born workers is widely acknowledged in highly skilled sectors such as science and engineering as well as less-skilled sectors such as labor-intensive agriculture. The distribution of workers within broad occupation categories displays patterns similar to those found among industrial sectors ( Table 8 ). In most occupational categories, the native born and foreign-born naturalized citizens resemble each other closely. Differences appear among foreign-born noncitizens who, on average, concentrate less in higher-skilled services and more in lower-skilled service and industrial occupations. In the one key exception, computer, science, and engineering occupations, noncitizen foreign born are comparable to naturalized citizens and the native born. These descriptive statistics confirm an earlier Census Bureau report which showed that citizens and those with extensive U.S. experience are more likely to resemble the native born in their occupational distribution. Broad occupation and industrial sector categories can mask the extent to which native-born or foreign-born nationals dominate some occupations. Table 9 presents, for a group of selected occupations, the proportions held by native and foreign-born men and women, by citizenship status. The table lists these selected occupations according to native-born male proportion, ranked lowest to highest. Native and foreign-born workers shown in Table 8 represent 84% and 16%, respectively, of the U.S. labor force. Differences between this national average and figures shown in Table 9 indicate cases of occupational imbalance by gender, nativity, or citizenship. In some heavily unionized occupations such as locomotive engineers and construction inspectors, native-born workers dominate. In other, less-skilled occupations with low barriers to entry, such as sewing machine operators, agricultural workers, and meat processing workers, the foreign-born noncitizen population is represented in numbers that far exceed their total averages. Yet the foreign born also exceed their national average proportion in certain specialty occupations that require substantial education, such as physical scientists, physicians and surgeons, and computer scientists reflecting the bifurcated education profile discussed earlier and presented in Figure 11 . Policymakers frequently rely on median income as an indicator of economic assimilation and productive output. On average, median incomes of native-born workers are higher than foreign-born workers. These differences vary substantially by citizenship and sex ( Table 10 ) but at higher education levels, they become minimal. In fact, no nativity gap in median income appears for female workers with at least a bachelor's degree. Among the foreign born, naturalized U.S. citizen incomes exceed noncitizen incomes by an average of 62%, reflecting higher educational attainment, and greater U.S. experience (see Table 10 ). The poverty threshold, another measure of economic well-being, is an income figure set annually by the Census Bureau, above or below which an individual or family is officially classified as poor. Poverty for the foreign born varies by citizenship status, with relatively smaller proportions of naturalized citizens and greater proportions of noncitizens falling below the poverty threshold ( Figure 13 ). The difference in poverty level between the native born and foreign-born noncitizens is 10%. If those below poverty and those earning 100-200% of the poverty threshold are combined (the "poor" plus the "near-poor"), then the difference between the native born (35%) and foreign-born noncitizens (56%) expands to 21%. Poverty rates among the foreign born relative to the native born ( Table 11 ) follow patterns borne out by much previous research. Relatively higher poverty rates are reported by women, persons in the early working age groups, and the less educated. The proportion of children falling below the poverty line is considerably higher than that of working-age adults for all groups. Among the foreign born, poverty rates are relatively higher for persons who arrived in the United State more recently. Persons from the Middle East, the Caribbean, and Mexico exhibit relatively high rates while those from Oceania, Canada, and Western Europe exhibit the lowest. The 39.9 million foreign born (in 2010) make up roughly one-eighth of the U.S. population, but between 2000 and 2010, they accounted for nearly one-third of all U.S. population growth. They include not only an estimated 14.8 million naturalized citizens (37% of all foreign born) but also 11.2 million unauthorized aliens. Of the 16.9 million children with at least one foreign-born parent in 2010, 14.5 million, or 86%, were born in the United States. Recent estimates indicate that unauthorized aliens, legal residents (permanent and temporary) and naturalized citizens made up 28%, 35% and 37%, respectively, of the foreign-born population. Years of U.S. experience and educational attainment are positively associated with citizenship status. Origins of the foreign born have shifted from Europe (74% in 1960) to Latin America and Asia (81% in 2010). While many foreign-born persons have settled recently in new urban and rural destinations, two-thirds of the foreign-born population lives in California, New York, Florida, Texas, Illinois, and New Jersey. Almost two thirds of all foreign born arrived to the United States after 1990. Between 2000 and 2010, foreign-born workers accounted for almost all the growth in the U.S. workforce between ages 25-54. As this CRS analysis illustrates, their labor force contributions to the U.S. economy range from low-skilled occupations in the agriculture, manufacturing, and service sectors to highly skilled occupations in science, engineering, medicine, nursing, defense, and other critical industrial sectors. The foreign born have lower average educational attainment and a higher proportion of persons without a high school diploma than the native born. However, the foreign-born and native-born populations possess the same proportion with at least a bachelor's degree. Lower education levels and differences in industrial sector and occupational distributions partly explain income and poverty differences between foreign-born and native-born workers; for those with at least a four-year college degree, earnings differences by nativity are minimal. Among the foreign born, median incomes of naturalized citizens are roughly 60% higher than those of noncitizens, reflecting higher education levels, older ages, and greater U.S. labor market experience. Poverty status is linked to the lack of citizenship, a difference that is magnified after including the "near-poor," who earn between 100% and 200% of the poverty threshold. Changes in the age composition of the American population can have a considerable impact on the U.S. labor force, on public sector expenditures, and consequently on U.S. public policy. Political debates over immigration policy may sometimes originate because of different priorities for public spending, as younger foreign-born persons and their children tend to demand different public services (e.g., public education and affordable housing) than older native-born residents (e.g., affordable health care). Data Sources and Limitations Unless indicated otherwise, data for this report come primarily from the Public Use Micro Sample (PUMS) of the 2010 American Community Survey (ACS). This survey is sent to roughly 250,000 households every month (or 3 million households every year) and replaces the long form questionnaire of the decennial census. As with the decennial census long form, the ACS collects information on socio-demographic characteristics, disability, English and native language use, income, and housing characteristics. The ACS has the advantage of continuous measurement by producing new data every year rather than every 10 years for the decennial census. However, because it is sent to far fewer households (1 in 100) compared to the decennial census (1 in 6) ACS estimates of the population and population characteristics have a relatively greater margin of error, particularly for smaller geographic areas. This report avoids that obstacle because it presents computations at a sufficiently large geographic unit of analysis, often at the national level. For instance, the 2010 ACS PUMS contains about 2,714,000 observations representing the native born, and 348,000 observations representing the foreign born, before weighting. As such, descriptive statistics presented herein are based upon sufficiently large sample sizes that support statistical validity at the 95% probability level. The PUMS is a publically available dataset that contains no personal identifiers and permits analysis of micro-level data across characteristics of one's choosing. Key Definitions Nativity , which refers to whether someone is native born or foreign born, generally refers to place of birth, but not exclusively. The Census Bureau defines native-born persons as those who were U.S. citizens or U.S. nationals at birth. Hence, in addition to persons born in the United States, the term native-born also includes persons born in a U.S. Commonwealth or other territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, or the Northern Mariana Islands), or born abroad to a U.S. citizen parent or parents. Anyone not born a U.S. citizen or U.S. national is defined as foreign born, including those who have become U.S. citizens through naturalization. Naturalized citizens are defined by the Immigration and Naturalization Act (INA) as persons admitted as legal residents who have lived in the United States continuously for at least five years; demonstrated good moral character as well as English reading, writing, and speaking ability; and passed an examination on U.S. history and government. If these legal permanent residents have their petitions for naturalization approved, they become U.S. citizens.

Summary: This report offers context for consideration of immigration policy options by presenting data on key geographic, demographic, social, and economic characteristics of the foreign-born population residing in the United States. Interest in the U.S. foreign-born population stems in part from the changing demographic profile of the United States as well as the rapidity of such change, and how both of these trends correspond to U.S. immigration policy. Although the foreign born are relatively small in absolute terms—39.9 million people representing 12.9% of the total U.S. population of 309.3 million in 2010—they are growing far more rapidly than the native-born population. Between 2000 and 2010, the foreign born contributed 32% of the total U.S. population increase and almost all of the prime 25-54 working age group increase. Almost one-third of the foreign born arrived in the United States since 2000, and an estimated 28% were residing illegally in the United States in 2010. Geographic origins of the foreign born have shifted from Europe (74% in 1960) to Latin America and Asia (81% in 2010). In recent years, many foreign born have settled in new urban and rural destinations, often in response to employment opportunities in construction, manufacturing, and low-skilled services. Yet, as in previous decades, at least two-thirds of the foreign born remain concentrated in just six states: California, New York, Florida, Texas, Illinois, and New Jersey. Several measures of marital status and household structure show little difference between the native born and foreign born. The foreign born have lower average educational attainment, but the proportion with at least a bachelor's degree matches that of the native born. In 2010, the foreign born accounted for 16.3% of all workers, with higher labor force participation rates among men and lower rates among women compared to native-born workers. With exceptions, native and foreign-born workers generally resemble each other in their distribution across broad industrial and occupational sectors. Among specific occupations, however, glaring differences occur, with native-born workers dominating occupations such as construction inspectors and librarians, and foreign-born workers dominating occupations such as agricultural laborers and tailors. Lower education levels and differences in industrial sector and occupational distributions explain in part why foreign-born workers have lower median incomes and higher poverty rates than native-born workers. Earnings differences are minimal for those with a four-year college degree. Among the foreign born, median incomes of naturalized citizens are 62% higher than those of noncitizens, reflecting higher education levels, older ages, and greater U.S. labor market experience. Poverty status is linked to the lack of citizenship, a difference that is magnified after including the "near-poor," who earn between 100% and 200% of the poverty threshold. Although foreign-born population growth and transformation often occur because of factors beyond the control of Congress—including political turmoil and natural disasters in neighboring countries and social and economic processes of globalization—how Congress crafts immigration law does influence the size and character of resulting immigration flows to the United States.