Approximately 41 million people immigrated to the United States of America between the years 1820 and 1957. During this time period, the United States expanded across North America, growing from 23 to 48 states, and the population grew from approximately 10 million people in 1820, to almost 180 million people by 1957. Economically, the U.S. developed from being an agriculturally focused economy in the 1820s, to having the highest GDP of any single country in the 1950s. Much of this expansion was due to the high numbers of agricultural workers who migrated from Europe, as technological advances in agriculture had lowered the labor demand. The majority of these migrants settled in urban centers, and this fueled the growth of the industrial sector.

American industrialization and European rural unemployment fuel migration The first major wave of migration came in the 1850s, and was fueled largely by Irish and German migrants, who were fleeing famine or agricultural depression at the time. The second boom came in the 1870s, as the country recovered from the American Civil War, and the Second Industrial Revolution took off. The final boom of the nineteenth century came in the 1880s, as poor harvests and industrialization in Europe led to mass emigration. Improvements in steam ship technology and lower fares led to increased migration from Eastern and Southern Europe at the turn of the century (particularly from Italy). War and depression reduces migration Migration to the U.S. peaked at the beginning of the 20th century, before it fluctuated greatly at the beginning of the 20th century. This was not only due to the disruptions to life in Europe caused by the world wars, but also the economic disruption of the Great Depression in the 1930s. The only period between 1914 and 1950 where migration was high was during the 1920s. However, the migration rate rose again in the late 1940s, particularly from Latin America and Asia. The historically high levels of migration from Europe has meant that the most common ethnicity in the U.S. has been non-Hispanic White since the early-colonial period, however increased migration from Latin America, Asia and Africa, and higher fertility rates among ethnic minorities, have seen the Whites' share of the total population fall in recent years (although it is still over three times larger than any other group.

United States Immigrants Admitted: All Countries data was reported at 1,127,167.000 Person in 2017. This records a decrease from the previous number of 1,183,505.000 Person for 2016. United States Immigrants Admitted: All Countries data is updated yearly, averaging 451,510.000 Person from Sep 1900 (Median) to 2017, with 118 observations. The data reached an all-time high of 1,827,167.000 Person in 1991 and a record low of 23,068.000 Person in 1933. United States Immigrants Admitted: All Countries data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s United States – Table US.G087: Immigration.

In 2022, an estimated 10.99 million unauthorized immigrants were living in the United States. This is an increase from about 3.5 million unauthorized immigrants who lived in the United States in 1990.

The estimated population of unauthorized immigrants in the U.S. stands at around 11 million people. Although the number has stabilized, the United States has seen a spike in migrant encounters in the last few years, with over two million cases registered by the U.S. Border Patrol in 2023. This is a slight decrease from the previous year, when there were over 2.2 million cases registered. Due to its proximity and shared border, Mexico remains the leading country of origin for most undocumented immigrants in the U.S., with California and Texas being home to the majority.

Immigration and political division

Despite the majority of the population having immigrant roots, the topic of immigration in the U.S. remains one of the country’s longest-standing political debates. Support among Republicans for restrictive immigration has grown alongside Democratic support for open immigration. This growing divide has deepened the polarization between the two major political parties, stifling constructive dialogue and impeding meaningful reform efforts and as a result, has led to dissatisfaction from all sides. In addition to general immigration policy, feelings toward illegal immigration in the U.S. also vary widely. For some, it's seen as a significant threat to national security, cultural identity, and economic stability. This perspective often aligns with support for stringent measures like Trump's proposed border wall and increased enforcement efforts. On the other hand, there are those who are more sympathetic toward undocumented immigrants, as demonstrated by support for the Deferred Action for Childhood Arrivals (DACA) program.

Between 1820 and 1957, over 4.6 million people emigrated from the island of Ireland to the United States. The period with the highest levels of migration came between 1845 and 1855 , as the Great Famine devastated Ireland's population, causing the deaths of roughly one million people and leading to the migration of one million more, most of which was to the United States. The period with the lowest levels of migration came in the 1930s and 40s, as the Great Depression and Second World War created an environment where migration to the US was difficult or impractical.

This data collection contains information on the characteristics of aliens who became legal permanent residents of the United States in fiscal year 1978 (October 1977 through September 1978). Data are presented for two types of immigrants. The first category, New Arrivals, arrived from outside the United States with valid immigrant visas issued by the United States Department of State. Those in the second category, Adjustments, were already in the United States with temporary status and were adjusted to legal permanent residence through petition to the United States Immigration and Naturalization Service. Variables include port of entry, month and year of admission, class of admission, and state and area to which immigrants were admitted. Demographic information such as age, sex, marital status, occupation, country of birth, country of last permanent residence, and nationality is also provided.

International migrant stock is the number of people born in a country other than that in which they live. It also includes refugees. The data used to estimate the international migrant stock at a particular time are obtained mainly from population censuses. The estimates are derived from the data on foreign-born population--people who have residence in one country but were born in another country. When data on the foreign-born population are not available, data on foreign population--that is, people who are citizens of a country other than the country in which they reside--are used as estimates. After the breakup of the Soviet Union in 1991 people living in one of the newly independent countries who were born in another were classified as international migrants. Estimates of migrant stock in the newly independent states from 1990 on are based on the 1989 census of the Soviet Union. For countries with information on the international migrant stock for at least two points in time, interpolation or extrapolation was used to estimate the international migrant stock on July 1 of the reference years. For countries with only one observation, estimates for the reference years were derived using rates of change in the migrant stock in the years preceding or following the single observation available. A model was used to estimate migrants for countries that had no data.

Between 1820 and 1957, more than six million people emigrated from Germany to the United States. The period with the highest levels of migration came during the 1850s and the 1880s, and over 250 thousand documented migrants came to the US from Germany in 1882 alone. The reasons for these mass migrations were not linked to individual events, but were because of the improved access to trans-Atlantic travel, poor economic opportunities at home (particularly for farmers, who struggled with the rapid industrialization of Germany), and to escape religious persecution in Europe. The periods with the lowest levels of migration from Germany were between 1915 and 1945, and were likely caused by the First and Second World Wars, and also the Great Depression.

The number of Mexican-born immigrants to the United States has increased significantly over time, although the number has begun to decrease in recent years. In 2023, there were over 10.91 million Mexican-born immigrants in the U.S., although this is a decrease from the peak of 11.7 million in 2010.

Public use data set on new legal immigrants to the U.S. that can address scientific and policy questions about migration behavior and the impacts of migration. A survey pilot project, the NIS-P, was carried out in 1996 to inform the fielding and design of the full NIS. Baseline interviews were ultimately conducted with 1,127 adult immigrants. Sample members were interviewed at baseline, 6 months, and 12 months, with half of the sample also interviewed at three months. The first full cohort, NIS-2003, is based on a nationally representative sample of the electronic administrative records compiled for new immigrants by the US government. NIS-2003 sampled immigrants in the period May-November 2003. The geographic sampling design takes advantage of the natural clustering of immigrants. It includes all top 85 Metropolitan Statistical Areas (MSAs) and all top 38 counties, plus a random sample of other MSAs and counties. Interviews were conducted in respondents'' preferred languages. The baseline was multi-modal: 60% of adult interviews were administered by telephone; 40% were in-person. The baseline round was in the field from June 2003 to June 2004, and includes in the Adult Sample 8,573 respondents, 4,336 spouses, and 1,072 children aged 8-12. A follow-up was planned for 2007. Several modules of the NIS were designed to replicate sections of the continuing surveys of the US population that provide a natural comparison group. Questionnaire topics include Health (self-reports of conditions, symptoms, functional status, smoking and drinking history) and use/source/costs of health care services, depression, pain; background; (2) Background: Childhood history and living conditions, education, migration history, marital history, military history, fertility history, language skills, employment history in the US and foreign countries, social networks, religion; Family: Rosters of all children; for each, demographic attributes, education, current work status, migration, marital status and children; for some, summary indicators of childhood and current health, language ability; Economic: Sources and amounts of income, including wages, pensions, and government subsidies; type, value of assets and debts, financial assistance given/received to/from respondent from/to relatives, friends, employer, type of housing and ownership of consumable durables. * Dates of Study: 2003-2007 * Study Features: Longitudinal * Sample Size: 13,981

International migrant stock is the number of people born in a country other than that in which they live. It also includes refugees. The data used to estimate the international migrant stock at a particular time are obtained mainly from population censuses. The estimates are derived from the data on foreign-born population--people who have residence in one country but were born in another country. When data on the foreign-born population are not available, data on foreign population--that is, people who are citizens of a country other than the country in which they reside--are used as estimates. After the breakup of the Soviet Union in 1991 people living in one of the newly independent countries who were born in another were classified as international migrants. Estimates of migrant stock in the newly independent states from 1990 on are based on the 1989 census of the Soviet Union. For countries with information on the international migrant stock for at least two points in time, interpolation or extrapolation was used to estimate the international migrant stock on July 1 of the reference years. For countries with only one observation, estimates for the reference years were derived using rates of change in the migrant stock in the years preceding or following the single observation available. A model was used to estimate migrants for countries that had no data.

This graph shows the distribution of nationalities among documented immigrants who arrived in the United States between 1820 and 1870. As we can see, over seven million people arrived in the US in this 50 year period, with the majority coming from Ireland, Germany and Britain. The largest groups, by far, were Irish and German, who together made up roughly two thirds of all immigrants to the US during this time. The reasons for this were because of the Irish Potato famine from 1845 to 1849, which resulted in the death or emigration of twenty to twenty five percent of the total Irish population, and a number of internal factors in Germany such as economic migration for farmers affected by industrialization, political/religious asylum, and in order to avoid conscription. One noteworthy exclusion from the information is of those transported to US as slaves, whose information was not recorded in this statistic (although the slave trade was abolished in 1808, the practice continued in the decades that followed).

United States Immigrants Admitted: United Kingdom data was reported at 10,948.000 Person in 2017. This records a decrease from the previous number of 12,673.000 Person for 2016. United States Immigrants Admitted: United Kingdom data is updated yearly, averaging 13,552.000 Person from Sep 1986 (Median) to 2017, with 32 observations. The data reached an all-time high of 19,973.000 Person in 1992 and a record low of 7,647.000 Person in 1999. United States Immigrants Admitted: United Kingdom data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s USA – Table US.G087: Immigration.

United States Immigrants Admitted: South America data was reported at 79,076.000 Person in 2017. This records a decrease from the previous number of 79,608.000 Person for 2016. United States Immigrants Admitted: South America data is updated yearly, averaging 72,183.000 Person from Sep 1986 (Median) to 2017, with 32 observations. The data reached an all-time high of 137,971.000 Person in 2006 and a record low of 41,007.000 Person in 1988. United States Immigrants Admitted: South America data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s USA – Table US.G087: Immigration.

United States Immigrants Admitted: Taiwan data was reported at 4,858.000 Person in 2017. This records a decrease from the previous number of 5,120.000 Person for 2016. United States Immigrants Admitted: Taiwan data is updated yearly, averaging 9,012.000 Person from Sep 1986 (Median) to 2017, with 32 observations. The data reached an all-time high of 16,344.000 Person in 1992 and a record low of 4,697.000 Person in 2014. United States Immigrants Admitted: Taiwan data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s United States – Table US.G087: Immigration.

VITAL SIGNS INDICATOR Migration (EQ4)

FULL MEASURE NAME Migration flows

LAST UPDATED December 2018

DESCRIPTION Migration refers to the movement of people from one location to another, typically crossing a county or regional boundary. Migration captures both voluntary relocation – for example, moving to another region for a better job or lower home prices – and involuntary relocation as a result of displacement. The dataset includes metropolitan area, regional, and county tables.

DATA SOURCE American Community Survey County-to-County Migration Flows 2012-2015 5-year rolling average http://www.census.gov/topics/population/migration/data/tables.All.html

CONTACT INFORMATION vitalsigns.info@bayareametro.gov

METHODOLOGY NOTES (across all datasets for this indicator) Data for migration comes from the American Community Survey; county-to-county flow datasets experience a longer lag time than other standard datasets available in FactFinder. 5-year rolling average data was used for migration for all geographies, as the Census Bureau does not release 1-year annual data. Data is not available at any geography below the county level; note that flows that are relatively small on the county level are often within the margin of error. The metropolitan area comparison was performed for the nine-county San Francisco Bay Area, in addition to the primary MSAs for the nine other major metropolitan areas, by aggregating county data based on current metropolitan area boundaries. Data prior to 2011 is not available on Vital Signs due to inconsistent Census formats and a lack of net migration statistics for prior years. Only counties with a non-negligible flow are shown in the data; all other pairs can be assumed to have zero migration.

Given that the vast majority of migration out of the region was to other counties in California, California counties were bundled into the following regions for simplicity: Bay Area: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, Sonoma Central Coast: Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz Central Valley: Fresno, Kern, Kings, Madera, Merced, Tulare Los Angeles + Inland Empire: Imperial, Los Angeles, Orange, Riverside, San Bernardino, Ventura Sacramento: El Dorado, Placer, Sacramento, Sutter, Yolo, Yuba San Diego: San Diego San Joaquin Valley: San Joaquin, Stanislaus Rural: all other counties (23)

One key limitation of the American Community Survey migration data is that it is not able to track emigration (movement of current U.S. residents to other countries). This is despite the fact that it is able to quantify immigration (movement of foreign residents to the U.S.), generally by continent of origin. Thus the Vital Signs analysis focuses primarily on net domestic migration, while still specifically citing in-migration flows from countries abroad based on data availability.

United States Immigrants Admitted: Russia data was reported at 9,297.000 Person in 2016. This records an increase from the previous number of 8,799.000 Person for 2015. United States Immigrants Admitted: Russia data is updated yearly, averaging 12,079.000 Person from Sep 1992 (Median) to 2016, with 25 observations. The data reached an all-time high of 20,771.000 Person in 2002 and a record low of 6,718.000 Person in 2010. United States Immigrants Admitted: Russia data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s USA – Table US.G086: Immigration.

International migrant stock is the number of people born in a country other than that in which they live. It also includes refugees. The data used to estimate the international migrant stock at a particular time are obtained mainly from population censuses. The estimates are derived from the data on foreign-born population--people who have residence in one country but were born in another country. When data on the foreign-born population are not available, data on foreign population--that is, people who are citizens of a country other than the country in which they reside--are used as estimates. After the breakup of the Soviet Union in 1991 people living in one of the newly independent countries who were born in another were classified as international migrants. Estimates of migrant stock in the newly independent states from 1990 on are based on the 1989 census of the Soviet Union. For countries with information on the international migrant stock for at least two points in time, interpolation or extrapolation was used to estimate the international migrant stock on July 1 of the reference years. For countries with only one observation, estimates for the reference years were derived using rates of change in the migrant stock in the years preceding or following the single observation available. A model was used to estimate migrants for countries that had no data.

Germany Immigration: America data was reported at 75,131.000 Person in 2023. This records an increase from the previous number of 71,252.000 Person for 2022. Germany Immigration: America data is updated yearly, averaging 49,202.000 Person from Dec 1964 (Median) to 2023, with 60 observations. The data reached an all-time high of 83,164.000 Person in 2006 and a record low of 32,711.000 Person in 1976. Germany Immigration: America data remains active status in CEIC and is reported by Statistisches Bundesamt. The data is categorized under Global Database’s Germany – Table DE.G005: Migration.

United States Immigrants Admitted: India data was reported at 60,394.000 Person in 2017. This records a decrease from the previous number of 64,687.000 Person for 2016. United States Immigrants Admitted: India data is updated yearly, averaging 53,766.000 Person from Sep 1986 (Median) to 2017, with 32 observations. The data reached an all-time high of 84,680.000 Person in 2005 and a record low of 26,227.000 Person in 1986. United States Immigrants Admitted: India data remains active status in CEIC and is reported by US Department of Homeland Security. The data is categorized under Global Database’s USA – Table US.G087: Immigration.