Immigration in the United States: how the system works
Immigration shaped the United States and remains one of its most contested political issues. About 15% of the population was born abroad. The legal system runs on a few main channels (family, work, humanitarian protection, and a visa lottery), while millions of people live in the country without legal status. This page explains the system, recent changes, and the main arguments, without taking a side.
This page provides general, neutral information only and is not legal or immigration advice. Rules have changed quickly since 2025, so check official sources such as USCIS and the State Department, or consult an immigration attorney.
A country built by immigration
Apart from Native Americans, the population descends from people who arrived over the past few centuries, including Africans brought by force through slavery. Voluntary immigration came in waves: from Britain and northern Europe in the colonial era; from Ireland, Germany, Italy, Scandinavia, and eastern Europe in the 19th and early 20th centuries; and from Latin America and Asia after a 1965 law ended national-origin quotas that had favored Europeans.
Ellis Island, near New York, processed millions of arrivals between 1892 and 1954. Restriction has its own long history too, from the Chinese Exclusion Act of 1882 to the quotas of the 1920s. Americans have long argued over whether newcomers blend into a "melting pot" or keep distinct cultures, as in a "salad bowl."
How legal immigration works
Immigration is a federal matter. Congress writes the law, mainly the Immigration and Nationality Act, and the executive branch applies it. Annual caps and per-country limits create waits that can run to years or decades for some applicants.
| Channel | Who it covers |
|---|---|
| Family | Spouses, parents, and unmarried children of citizens without a cap; other relatives within capped categories |
| Employment | Workers sponsored by employers or with exceptional skills, within annual caps |
| Humanitarian | Refugees selected abroad and asylum seekers already in or arriving in the US |
| Diversity visa | A lottery of up to 55,000 visas a year for countries with low recent immigration |
People on temporary visas come as visitors, students, or workers. Permanent residents hold a green card, and most can apply for citizenship after five years, or three if married to a citizen.
| Status | Can live here long term? | Can vote in federal elections? |
|---|---|---|
| Temporary visa holder | Only for the visa's purpose and length | No |
| Green card holder | Yes | No |
| Naturalized citizen | Yes | Yes |
Three agencies, all within the Department of Homeland Security, do most of the work: USCIS handles applications, CBP runs the border and ports of entry, and ICE handles enforcement inside the country. Consulates abroad, under the State Department, issue visas. Immigration courts sit in the Justice Department, not the regular judiciary.
People without legal status
Pew Research Center estimated a record 14 million unauthorized immigrants in 2023, up from the roughly 11 million often cited in earlier years. Its preliminary data pointed to a decline in the overall immigrant population during 2025, from about 53 million to 52 million, though those survey figures are preliminary. Estimates vary by method, and no count is exact.
Not everyone without status crossed a border illegally. Many entered on a visa and stayed past its expiry. Immigrants without status are generally ineligible for most federal benefits, though they pay taxes in many cases, and children can attend public school regardless of status.
DACA and the Dreamers
DACA (Deferred Action for Childhood Arrivals), created by executive action in 2012, gives work permits and temporary protection from deportation to certain people brought to the US as children. It is not a legal status or a route to citizenship. A federal appeals court ruled against the program in 2025 but limited the effect to Texas. Renewals have continued while new applications have remained largely stalled. Its future depends on the courts and Congress.
What has changed since 2025
The second Trump administration has moved quickly, and much of this has been challenged in court. Check the current position before acting on any of these points.
- Border: illegal crossings at the southern border fell sharply in 2025, to their lowest levels in decades, and asylum access at the border was tightly restricted.
- Enforcement: a 2025 budget law provided large new funding for ICE, detention, and border barriers. ICE reported more than 356,000 removals between October 2025 and mid-July 2026.
- Travel restrictions: a proclamation in effect from January 2026 fully or partly suspended entry from dozens of countries. Separately, the State Department paused immigrant visas for nationals of 75 countries in January 2026, a step contested in court.
- Refugees: the annual refugee ceiling was cut to 7,500 for fiscal 2026, by far the lowest since the program began in 1980.
- H-1B: a $100,000 payment on certain new petitions, announced in 2025, was rejected by federal courts in Massachusetts and California in 2026 after another court had upheld it, and litigation was continuing.
Birthright citizenship
The Fourteenth Amendment makes people born in the US citizens. A January 2025 executive order sought to deny this to children of parents who are here unlawfully or temporarily. In Trump v. Barbara (June 30, 2026), the Supreme Court ruled 6-3 that the order violated the Citizenship Clause. A second executive order followed in August 2026, and advocacy groups have challenged it. See the US Constitution.
States and cities
The federal government sets the rules, but states and cities shape how they land, as our page on states vs. the federal government explains. Some, such as Texas and Florida, work closely with federal enforcement. Others, such as California and Illinois, limit local cooperation in so-called sanctuary policies. Courts have held that states cannot run their own immigration systems, and that Washington cannot force local police to enforce federal immigration law.
The debate
Positions do not always follow party lines, and many people hold views in between, such as tougher border security combined with more legal pathways. Congress has debated comprehensive reform repeatedly, most seriously in 2006, 2007, and 2013, without passing it.
Arguments for more openness
- Immigration supports growth, fills labor shortages, and offsets an aging population.
- People settled for many years deserve a path to legal status.
- Offering asylum is a humanitarian and legal commitment.
Arguments for tighter control
- The rule of law requires enforcing entry and residency rules.
- Border control is a matter of sovereignty and security.
- Large inflows can strain local services and put pressure on wages in some jobs.
Research on the overall economic effects is contested. Findings differ with the time frame, the workers studied, and whether federal or local budgets are measured. Immigrants work across the economy, from science and medicine to farming, construction, and care work.
Frequently asked questions
How many immigrants live in the US?
Roughly 52 million, or about 15% of the population, according to Pew Research Center's estimates for 2025. That includes citizens, green card holders, temporary residents, and people without legal status.
How many undocumented immigrants are in the US?
Pew estimated 14 million in 2023, the most recent full estimate, and preliminary data suggest numbers may have fallen since 2025. All such figures are approximate.
What is the difference between a green card and citizenship?
A green card gives the right to live and work in the US permanently. Citizenship adds a US passport, the right to vote, and protection from deportation, and it usually requires years of residence, a test, and an oath.
Who are the Dreamers?
People brought to the US as children without legal status. DACA protects some of them temporarily, but it does not provide a permanent status.
Is a child born in the US automatically a citizen?
Yes, with narrow exceptions such as children of foreign diplomats. The Supreme Court reaffirmed this in June 2026 when it struck down the executive order limiting birthright citizenship.
This page provides general, neutral information only and does not constitute immigration advice.
Related articles: