The estimated population of unauthorized immigrants in the U.S. stands at around ** million people. Although the number has stabilized, the United States has seen a spike in migrant encounters in the last few years, with over * million cases registered by the U.S. Border Patrol in 2023. This is a slight decrease from the previous year, when there were over *** 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.

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.

In 2024, there were approximately 239,159 illegal border crossings made at borders of the European Union, with Syrian's being the most common nationality, at 44,237.

In 2022, about **** million illegal aliens were apprehended in the United States. This was a significant increase from the previous year, when there were around **** million illegal aliens apprehended nationwide. Apprehensions refer to Border Patrol apprehensions and ICE administrative arrests.

In January 2022, it was estimated that about 1.85 million male illegal immigrants living in the United States were aged between 35 and 44 years old. In that same year, it was estimated that 1.52 million female illegal immigrants living in the U.S. were between 35 and 44 years old.

This study was conducted to examine whether a rising crime rate in El Paso, Texas and San Diego, California in 1986 could be attributed to, among other factors, the influx of undocumented aliens. Variables include level of involvement of undocumented aliens in serious felony arrests in San Diego and El Paso Counties, the outcome of serious felony arrest cases involving undocumented persons compared to others arrested for similar offenses, the impact of arrests of undocumented aliens on the criminal justice system in terms of workload and cost, the extent that criminal justice agencies coordinate their efforts to apprehend and process undocumented aliens who have committed serious crimes in San Diego and El Paso counties, and how differences in agency objectives impede or enhance coordination. Data are also provided on how many undocumented persons were arrested/convicted for repeat offense in these counties and which type of policies or procedures could be implemented in criminal justice agencies to address the issue of crimes committed by undocumented aliens. Data were collected in the two cities with focus on serious felony offenses. The collection includes sociodemographic characteristics, citizenship status, current arrest, case disposition, and prior criminal history with additional data from San Diego to compute the costs involving undocumented aliens.

In 2019, California had the highest population of unauthorized immigrants, at around **** million. The overall figure for the United States was estimated to be around ***** million unauthorized immigrants.

As of January 2022, it was estimated that about 4.81 million illegal immigrants from Mexico were living in the United States. It was also estimated that 750,000 illegal immigrants from Guatemala were living in the United States.

Acknowledgement

The following table is imported from the 2019 Yearbook of Immigration Statistics under the Department of Homeland Security:

The 2019 Yearbook of Immigration Statistics is a compendium of tables that provide data on foreign nationals who are granted lawful permanent residence (i.e., immigrants who receive a “green card”), admitted as temporary nonimmigrants, granted asylum or refugee status, or are naturalized. The Yearbook also presents data on immigration enforcement actions, including apprehensions and arrests, removals, and returns.

Table 39. Aliens Removed or Returned: Fiscal Years 1892 to 2019 (https://www.dhs.gov/immigration-statistics/yearbook/2019/table39)

Inspiration

The data was collected to observe trends in history reflecting the number of immigrants deported - more specifically removed or returned.

In 2016, New York City designed and implemented an intervention to reduce frictions in accessing safety-net care: randomly making initial primary care appointments for 2,428 undocumented immigrants. We leverage a novel survey-administrative data linkage to show that the program increased self-reported access to primary care, leading to 23% fewer emergency department (ED) visits. High-risk individuals' ED visits fell by 32% on average, driving the aggregate effect. Preventive care also increased among individuals visiting sponsored clinics.

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.

Unauthorized population estimates for 1990, 2000, and 2014.

Dataset from Immigration and Checkpoints Authority. For more information, visit https://data.gov.sg/datasets/d_1dc58c8dc5ebd00aa4fcfa3c62ad162f/view