Definition
The act of coming into a country of which one is not a native or citizen, for the purpose of taking up permanent residence. Immigration is distinct from temporary entry: a tourist, student, or short-term worker enters a country without necessarily immigrating. The controlling intention — permanent or indefinite residence — has historically separated immigrants from other categories of foreign entrants, though modern statutory frameworks have complicated this line by creating long-term temporary statuses that occupy a middle ground.
In contemporary U.S. law, immigration encompasses the full system of rules governing who may lawfully enter, remain in, and acquire permanent status or citizenship in the United States. This includes visa categories, grounds of admission, grounds of inadmissibility and deportability, asylum and refugee protection, naturalization, and removal proceedings. The body of law is primarily federal, grounded in Congress's plenary power over immigration, and administered through agencies including the Department of Homeland Security (DHS), the Department of State, the Department of Justice's Executive Office for Immigration Review (EOIR), and the Department of Labor.
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Common Language
Modern common usage (Wiktionary): The act of coming into a country of which one is not native born for the purpose of permanent residence; also, colloquially, the process of going through immigration checks at a border checkpoint.
Historical common usage (Webster's 1913): The act of immigrating; the passing or coming into a country for the purpose of permanent residence.
The common and legal definitions are largely aligned on the core meaning. The gap lies in scope: in ordinary conversation, "immigration" often refers simply to movement of people across borders, including temporary travel. In legal usage, immigration has a precise consequence — it triggers a body of statutory rights, prohibitions, and procedures that attach to the entrant's status and intent. The checkpoint usage in modern common speech conflates the process of border inspection with the legal classification of the person being inspected.
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Common Confusion
Immigration is frequently conflated with naturalization and with citizenship. Immigration concerns entry and lawful presence; naturalization is the formal legal process by which a lawful permanent resident acquires citizenship. A person may immigrate, reside lawfully for years, and never naturalize. The three concepts represent sequential stages, not synonyms.
Immigration is also sometimes confused with migration in casual use. Migration is the broader term covering all human movement, including internal movement within a country; immigration is specifically international movement into a receiving country.
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Why It Matters in Research
The term's meaning has expanded dramatically from its historical definition. Historical sources define immigration almost entirely as a factual act — a person moving from one country to another intending permanence — with minimal legal superstructure attached. Researchers working in the historical corpus will find little treatment of immigration as an independent field of law. The modern system of visa categories, numerical caps, grounds of inadmissibility, and administrative courts emerged primarily in the twentieth century, accelerating after the Immigration and Nationality Act of 1952 and its major amendments in 1965 and 1986.
Researchers consulting historical dictionaries for immigration law doctrine should treat those sources as background on terminology only, not as guides to the legal system. The plenary power doctrine — Congress's near-unreviewable authority over immigration — appears nowhere in the historical dictionaries covered here but is foundational to understanding how federal courts have treated immigration statutes.
Jurisdictional research traps: Because immigration is a federal field, state cases and statutes are rarely authoritative on substantive immigration law, though they frequently intersect with it (employment, housing, education, public benefits). Researchers conflating state and federal authority in this area risk significant error.
The historical duty reference in Anderson's and Bouvier's — the fifty-cent head tax under the Act of August 3, 1882 — is a significant corpus signal. That statute was one of the first federal immigration control measures and was upheld as a regulation of commerce. Its presence in these entries reflects the moment when Congress first began constructing the administrative immigration system; it is not a reflection of any settled doctrine on immigration law as it is understood today.
Cross-corpus alert: Entries on immigration in the historical dictionaries bleed into emigration, naturalization, and alien. Researchers should pull all four terms when reconstructing the historical framework, as the concepts were not always cleanly separated in older legal writing.
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Historical Dictionary Support
All five historical sources agree on the core definition: immigration is the coming into a country for permanent residence, distinguished from emigration, which is the leaving of one's former country. This consensus is unsurprising — the term's basic meaning was uncontroversial. The dictionaries reflect an era when the legal significance of the act was minimal compared to the elaborate statutory regime that would follow.
Rapalje & Lawrence adds useful terminological precision: the same person is an emigrant at departure and an immigrant upon arrival — a distinction between perspective and position that modern administrative law implicitly preserves (different agencies govern departure from a sending country and admission to the receiving one).
Bouvier's and Anderson's both reproduce the 1882 head tax, which is the most substantive legal content any of these entries contain. This is historically important as evidence of where immigration law stood at the time of these dictionaries' publication: entry was beginning to be regulated, but the comprehensive framework of status, visa categories, and administrative courts had not yet emerged.
What the historical sources miss entirely: the plenary power doctrine, the concept of lawful permanent resident status (the green card), grounds of inadmissibility and deportability, the asylum system, removal proceedings, or any administrative adjudicative structure. Researchers should not infer from the brevity of these entries that immigration law was correspondingly simple — the entries predate most of the legal architecture that makes immigration a distinct and complex field.
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Jurisdictional Note
Immigration law in the United States is exclusively federal. States may not enact independent immigration admission or removal schemes, though state law frequently intersects with immigration status in areas such as employment verification, driver licensing, and access to public programs. Researchers in non-U.S. legal systems will find the U.S. administrative structure — with its specialized immigration courts under EOIR and appellate review through the BIA — distinctive and not universally applicable to other jurisdictions' immigration frameworks.
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Encyclopedia Cross-Reference
Immigration Law — Administrative Structure of the Immigration System (The Law Mind Administrative Law & Government Encyclopedia)
Immigration Court and the Board of Immigration Appeals (BIA) (The Law Mind Administrative Law & Government Encyclopedia)
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