Immigration law deals with whether a person is a legal resident, and, given their residency status, what their legal rights, obligations and duties are. The Immigration and Nationality Act of 1952 governs much of immigration law. Under this act, the definition of a resident alien is any individual that is not a citizen or national of the USA. The Act also outlines routes by which non-citizens may become naturalized citizens, what non-citizens are allowed to enter the United States, how long they may stay and when they must depart.
There are several different categories of non-citizen residents, including undocumented, documented, immigrant, non-immigrant, non-resident and resident. Immigration law is under the purview of Congress; the power of the president is restricted to policies on refugees. The courts typically stay out of this area unless there are constitutional matters that need to be addressed.
Over time, there have been a number of laws put into place to boost the regulation of illegal immigration practices. Local governments have attempted to crack down on sham marriages performed for one spouse to gain entry into the country. The federal and some state governments are also beginning t place more emphasis on punishment for those hiring illegal immigrants. The Immigration Reform and Control Act (1986) introduced strict punishments for companies that hire illegal immigrants.