100+ datasets found
  1. U.S. percentage of foreign-born population 2023, by state

    • statista.com
    • ai-chatbox.pro
    Updated Nov 7, 2024
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Statista (2024). U.S. percentage of foreign-born population 2023, by state [Dataset]. https://www.statista.com/statistics/312701/percentage-of-population-foreign-born-in-the-us-by-state/
    Explore at:
    Dataset updated
    Nov 7, 2024
    Dataset authored and provided by
    Statistahttp://statista.com/
    Time period covered
    2023
    Area covered
    United States
    Description

    As of 2023, 27.3 percent of California's population were born in a country other than the United States. New Jersey, New York, Florida, and Nevada rounded out the top five states with the largest population of foreign born residents in that year. For the country as a whole, 14.3 percent of residents were foreign born.

  2. Unauthorized immigrant population U.S. 1990-2022

    • statista.com
    Updated Jul 5, 2024
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Statista (2024). Unauthorized immigrant population U.S. 1990-2022 [Dataset]. https://www.statista.com/statistics/646261/unauthorized-immigrant-population-in-the-us/
    Explore at:
    Dataset updated
    Jul 5, 2024
    Dataset authored and provided by
    Statistahttp://statista.com/
    Area covered
    United States
    Description

    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.

  3. F

    Population Level - Foreign Born

    • fred.stlouisfed.org
    json
    Updated Jul 3, 2025
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2025). Population Level - Foreign Born [Dataset]. https://fred.stlouisfed.org/series/LNU00073395
    Explore at:
    jsonAvailable download formats
    Dataset updated
    Jul 3, 2025
    License

    https://fred.stlouisfed.org/legal/#copyright-public-domainhttps://fred.stlouisfed.org/legal/#copyright-public-domain

    Description

    Graph and download economic data for Population Level - Foreign Born (LNU00073395) from Jan 2007 to Jun 2025 about foreign, civilian, population, and USA.

  4. b

    Hardest Working Immigrant Population by U.S. State

    • brookslawfirm.com
    Updated May 16, 2025
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2025). Hardest Working Immigrant Population by U.S. State [Dataset]. https://brookslawfirm.com/blog/study-the-hardest-working-immigrant-populations-in-the-united-states/
    Explore at:
    Dataset updated
    May 16, 2025
    License

    CC0 1.0 Universal Public Domain Dedicationhttps://creativecommons.org/publicdomain/zero/1.0/
    License information was derived automatically

    Area covered
    United States
    Description

    This chart looks at the U.S. states with the largest number of workers per 100k immigrants, specifically looking at the 10 states with the highest percentage of workers per 100k immigrants.

  5. H

    American Community Survey of the Foreign Born

    • dataverse.harvard.edu
    • search.datacite.org
    Updated Nov 30, 2010
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Harvard Dataverse (2010). American Community Survey of the Foreign Born [Dataset]. http://doi.org/10.7910/DVN/EENUJP
    Explore at:
    CroissantCroissant is a format for machine-learning datasets. Learn more about this at mlcommons.org/croissant.
    Dataset updated
    Nov 30, 2010
    Dataset provided by
    Harvard Dataverse
    License

    CC0 1.0 Universal Public Domain Dedicationhttps://creativecommons.org/publicdomain/zero/1.0/
    License information was derived automatically

    Description

    Users can obtain demographic characteristics of the foreign-born population in each state. Topics include: language, education, income, and poverty. Background The American Community Survey and Census Data on the Foreign-Born interactive map was created by the Migration Policy Institute using Census data. This website provides information pertaining to the immigrant population in the United States. Topics include: demographics, language, education, income and poverty of the foreign-born population. User Functionality Users can click on states to generate fact sheets about the demographic, social, language, educ ation, workforce, income, and poverty characteristics of the population in each state. Data can be downloaded into SAS statistical software. Users can view demographic information by race/ethnicity, Hispanic origin, place of origin, citizenship status, sex/gender, and marital status. Data Notes Data are derived from the 1990 and 2000 Decennial Censuses and the 2007 American Community Surveys (ACS). Information is available on national and state levels. The website does not indicate when the data will be updated.

  6. Foreign-born population in the U.S. 1850-2023

    • statista.com
    Updated Jul 11, 2025
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Statista (2025). Foreign-born population in the U.S. 1850-2023 [Dataset]. https://www.statista.com/statistics/977670/foreign-born-population-united-states/
    Explore at:
    Dataset updated
    Jul 11, 2025
    Dataset authored and provided by
    Statistahttp://statista.com/
    Area covered
    United States
    Description

    In 2023, there were **** million foreign-born individuals living in the United States, an increase from **** million in 2000.

  7. g

    Immigrants Admitted to the United States, 1999

    • datasearch.gesis.org
    • icpsr.umich.edu
    v2
    Updated Aug 5, 2015
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    United States Department of Justice. Immigration and Naturalization Service (2015). Immigrants Admitted to the United States, 1999 [Dataset]. http://doi.org/10.3886/ICPSR03485.v2
    Explore at:
    v2Available download formats
    Dataset updated
    Aug 5, 2015
    Dataset provided by
    da|ra (Registration agency for social science and economic data)
    Authors
    United States Department of Justice. Immigration and Naturalization Service
    Area covered
    United States
    Description

    This data collection contains information on the characteristics of aliens who became legal permanent residents of the United States in fiscal year 1999 (October 1998 through September 1999). Data are presented for two types of immigrants. The first category, New Arrivals, arrived from outside the United States with valid immigration visas issued by the United States Immigration and Naturalization Service. 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 the 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.

  8. n

    2020 Foreign-Born Population

    • linc.osbm.nc.gov
    csv, excel, geojson +1
    Updated Jun 23, 2022
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2022). 2020 Foreign-Born Population [Dataset]. https://linc.osbm.nc.gov/explore/dataset/2020-foreign-born-population/
    Explore at:
    excel, json, geojson, csvAvailable download formats
    Dataset updated
    Jun 23, 2022
    Description

    2016-2020 Foreign-Born population by place of birth as reported by the US Census Bureau's, American Community Survey (ACS) 5-year estimates. Economic impact of the foreign-born population is based on the George Washington University Institute of Public Policy "Counting for Dollars: The Role of the Decennial Census in the Geographic Distribution of Federal Funds."

  9. n

    Data from: New Immigrant Survey

    • neuinfo.org
    • scicrunch.org
    • +2more
    Updated Jan 29, 2022
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2022). New Immigrant Survey [Dataset]. http://identifiers.org/RRID:SCR_008973
    Explore at:
    Dataset updated
    Jan 29, 2022
    Description

    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

  10. U.S. immigrant population, by education level and ethnicity 2010

    • statista.com
    Updated Jun 19, 2012
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Statista (2012). U.S. immigrant population, by education level and ethnicity 2010 [Dataset]. https://www.statista.com/statistics/233721/us-immigrant-population-with-a-college-education-by-ethnicity/
    Explore at:
    Dataset updated
    Jun 19, 2012
    Dataset authored and provided by
    Statistahttp://statista.com/
    Time period covered
    2010
    Area covered
    United States
    Description

    This statistic shows the percentage of recent immigrants in the United States as of 2010, by their level of education and also ethnicity. 65 percent of Asian immigrants either had a college degree or were in the process of completing a college degree at the time of this survey.

  11. United States US: Net Migration

    • ceicdata.com
    Updated Mar 15, 2023
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    CEICdata.com (2023). United States US: Net Migration [Dataset]. https://www.ceicdata.com/en/united-states/population-and-urbanization-statistics/us-net-migration
    Explore at:
    Dataset updated
    Mar 15, 2023
    Dataset provided by
    CEIC Data
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Time period covered
    Dec 1, 1962 - Dec 1, 2012
    Area covered
    United States
    Variables measured
    Population
    Description

    United States US: Net Migration data was reported at 4,500,000.000 Person in 2017. This stayed constant from the previous number of 4,500,000.000 Person for 2012. United States US: Net Migration data is updated yearly, averaging 4,213,405.500 Person from Dec 1962 (Median) to 2017, with 12 observations. The data reached an all-time high of 8,612,074.000 Person in 1997 and a record low of 1,549,465.000 Person in 1967. United States US: Net Migration data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United States – Table US.World Bank.WDI: Population and Urbanization Statistics. Net migration is the net total of migrants during the period, that is, the total number of immigrants less the annual number of emigrants, including both citizens and noncitizens. Data are five-year estimates.; ; United Nations Population Division. World Population Prospects: 2017 Revision.; Sum;

  12. The Unauthorized Immigrant in Minnesota

    • library.ncge.org
    Updated Jul 27, 2021
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    NCGE (2021). The Unauthorized Immigrant in Minnesota [Dataset]. https://library.ncge.org/documents/NCGE::the-unauthorized-immigrant-in-minnesota--1/about
    Explore at:
    Dataset updated
    Jul 27, 2021
    Dataset provided by
    National Council for Geographic Educationhttp://www.ncge.org/
    Authors
    NCGE
    License

    Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA 4.0)https://creativecommons.org/licenses/by-nc-sa/4.0/
    License information was derived automatically

    Area covered
    Minnesota
    Description

    Author: J Schiebel, educator, Minnesota Alliance for Geographic EducationGrade/Audience: grade 8Resource type: lessonSubject topic(s): migrationRegion: united statesStandards: Standard 5. The characteristics, distribution and migration of human populations on the earth’s surface influence human systems (cultural, economic and political systems).Objectives: Students will be able to:

    1. Identify push and pull factors of immigration. 2 Identify the types of immigrants including illegal, refugees, and asylum seekers (asylee).
    2. Identify their family's immigrant history.
    3. Describe Minnesota's immigrant populations, focusing on unauthorized immigrants from Mexico.
    4. Create a brief, fact-based editorial in support of or opposed to unauthorized immigration.Summary: This lesson will focus on understanding the reasons behind the movement of unauthorized (illegal) immigrants from Mexico to Minnesota and helping develop an informed opinion about the subject.
  13. F

    Employment Level - Foreign Born

    • fred.stlouisfed.org
    json
    Updated Jul 3, 2025
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2025). Employment Level - Foreign Born [Dataset]. https://fred.stlouisfed.org/series/LNU02073395
    Explore at:
    jsonAvailable download formats
    Dataset updated
    Jul 3, 2025
    License

    https://fred.stlouisfed.org/legal/#copyright-public-domainhttps://fred.stlouisfed.org/legal/#copyright-public-domain

    Description

    Graph and download economic data for Employment Level - Foreign Born (LNU02073395) from Jan 2007 to Jun 2025 about foreign, household survey, employment, and USA.

  14. United States US: International Migrant Stock: % of Population

    • ceicdata.com
    Updated Mar 15, 2023
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    CEICdata.com (2023). United States US: International Migrant Stock: % of Population [Dataset]. https://www.ceicdata.com/en/united-states/population-and-urbanization-statistics/us-international-migrant-stock--of-population
    Explore at:
    Dataset updated
    Mar 15, 2023
    Dataset provided by
    CEIC Data
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Time period covered
    Dec 1, 1990 - Dec 1, 2015
    Area covered
    United States
    Variables measured
    Population
    Description

    United States US: International Migrant Stock: % of Population data was reported at 14.491 % in 2015. This records an increase from the previous number of 14.258 % for 2010. United States US: International Migrant Stock: % of Population data is updated yearly, averaging 12.782 % from Dec 1990 (Median) to 2015, with 6 observations. The data reached an all-time high of 14.491 % in 2015 and a record low of 9.196 % in 1990. United States US: International Migrant Stock: % of Population data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United States – Table US.World Bank.WDI: Population and Urbanization Statistics. 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.; ; United Nations Population Division, Trends in Total Migrant Stock: 2008 Revision.; Weighted average;

  15. d

    Data from: Estimates of the Unauthorized Immigrant Population Residing in...

    • catalog.data.gov
    Updated Aug 1, 2021
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Under Secretary / Management (2021). Estimates of the Unauthorized Immigrant Population Residing in the United States: January 2005 [Dataset]. https://catalog.data.gov/lt/dataset/estimates-of-the-unauthorized-immigrant-population-residing-in-the-united-states-january-2-35851
    Explore at:
    Dataset updated
    Aug 1, 2021
    Dataset provided by
    Under Secretary / Management
    Area covered
    United States
    Description

    This report provides estimates of the number ofunauthorized immigrants residing in the United Statesin January 2005 by period of entry, country of origin,and state of residence.

  16. F

    Unemployment Rate - Foreign Born

    • fred.stlouisfed.org
    json
    Updated Jul 3, 2025
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2025). Unemployment Rate - Foreign Born [Dataset]. https://fred.stlouisfed.org/series/LNU04073395
    Explore at:
    jsonAvailable download formats
    Dataset updated
    Jul 3, 2025
    License

    https://fred.stlouisfed.org/legal/#copyright-public-domainhttps://fred.stlouisfed.org/legal/#copyright-public-domain

    Description

    Graph and download economic data for Unemployment Rate - Foreign Born (LNU04073395) from Jan 2007 to Jun 2025 about foreign, 16 years +, household survey, unemployment, rate, and USA.

  17. M

    North America Immigration Statistics

    • macrotrends.net
    csv
    Updated May 31, 2025
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    MACROTRENDS (2025). North America Immigration Statistics [Dataset]. https://www.macrotrends.net/global-metrics/countries/nac/north-america/immigration-statistics
    Explore at:
    csvAvailable download formats
    Dataset updated
    May 31, 2025
    Dataset authored and provided by
    MACROTRENDS
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Area covered
    north-america, United States
    Description
    North America immigration statistics for 2015 was 54,481,730, a 6.38% increase from 2010.
    <ul style='margin-top:20px;'>
    
    <li>North America immigration statistics for 2010 was <strong>51,213,753</strong>, a <strong>12.92% increase</strong> from 2005.</li>
    <li>North America immigration statistics for 2005 was <strong>45,355,554</strong>, a <strong>12.42% increase</strong> from 2000.</li>
    <li>North America immigration statistics for 2000 was <strong>40,343,635</strong>, a <strong>21.03% increase</strong> from 1995.</li>
    </ul>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.
    
  18. F

    Civilian Labor Force Level - Foreign Born

    • fred.stlouisfed.org
    json
    Updated Jul 3, 2025
    + more versions
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    (2025). Civilian Labor Force Level - Foreign Born [Dataset]. https://fred.stlouisfed.org/series/LNU01073395
    Explore at:
    jsonAvailable download formats
    Dataset updated
    Jul 3, 2025
    License

    https://fred.stlouisfed.org/legal/#copyright-public-domainhttps://fred.stlouisfed.org/legal/#copyright-public-domain

    Description

    Graph and download economic data for Civilian Labor Force Level - Foreign Born (LNU01073395) from Jan 2007 to Jun 2025 about foreign, civilian, 16 years +, labor force, labor, household survey, and USA.

  19. Top 10 areas in U.S. with biggest unauthorized immigrant populations in 2014...

    • statista.com
    Updated Aug 8, 2024
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    Statista (2024). Top 10 areas in U.S. with biggest unauthorized immigrant populations in 2014 [Dataset]. https://www.statista.com/statistics/675829/top-ten-areas-in-us-with-most-unauthorized-immigrants/
    Explore at:
    Dataset updated
    Aug 8, 2024
    Dataset authored and provided by
    Statistahttp://statista.com/
    Time period covered
    2014
    Area covered
    United States
    Description

    This statistic shows the top ten metropolitan areas in the United States with highest unauthorized immigrant populations in 2014. With over one million unauthorized people, New York-Newark-Jersey City, NY-NJ-PA had the highest illegal immigrant population in the United States in 2014.

  20. g

    Immigrants Admitted to the United States, Transitional Quarter 1976

    • datasearch.gesis.org
    • icpsr.umich.edu
    v1
    Updated Aug 5, 2015
    Share
    FacebookFacebook
    TwitterTwitter
    Email
    Click to copy link
    Link copied
    Close
    Cite
    United States Department of Justice. Immigration and Naturalization Service (2015). Immigrants Admitted to the United States, Transitional Quarter 1976 [Dataset]. http://doi.org/10.3886/ICPSR08957.v1
    Explore at:
    v1Available download formats
    Dataset updated
    Aug 5, 2015
    Dataset provided by
    da|ra (Registration agency for social science and economic data)
    Authors
    United States Department of Justice. Immigration and Naturalization Service
    Area covered
    United States
    Description

    This data collection contains information on the characteristics of aliens who became legal permanent residents of the United States in the transitional quarter of fiscal year 1976. (This transitional quarter, July-September 1976, is the period in which the Federal Government was making the transition from a July-June fiscal year to an October-September fiscal year.) 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.

Share
FacebookFacebook
TwitterTwitter
Email
Click to copy link
Link copied
Close
Cite
Statista (2024). U.S. percentage of foreign-born population 2023, by state [Dataset]. https://www.statista.com/statistics/312701/percentage-of-population-foreign-born-in-the-us-by-state/
Organization logo

U.S. percentage of foreign-born population 2023, by state

Explore at:
3 scholarly articles cite this dataset (View in Google Scholar)
Dataset updated
Nov 7, 2024
Dataset authored and provided by
Statistahttp://statista.com/
Time period covered
2023
Area covered
United States
Description

As of 2023, 27.3 percent of California's population were born in a country other than the United States. New Jersey, New York, Florida, and Nevada rounded out the top five states with the largest population of foreign born residents in that year. For the country as a whole, 14.3 percent of residents were foreign born.

Search
Clear search
Close search
Google apps
Main menu