When prompted to think about the subject of permanent residency Regarding a nation's own citizen, imaginably, immigration laws do not apply. In that case, international precedent takes over, and according to provisions made by the United Nations, a nation cannot refuse one of its own. Regarding a citizen from a foreign nation, therefore, immigration law does apply.
Whereas the basic human rights of people are spelled out by international assemblies such as the United Nations and conventions held therein, the immigration laws of a particular nation are subject to its own discretion. As such, the practice and enforcement of immigration law can vary in pronounced ways from place to place. While sharing a common lineage, the modern immigration laws of, say, the United States and England are separate entities entirely.
Narrowing our focus to immigration law in the United States, we notice that the primary governing body which oversees immigration and citizenship services has changed over time, and quite recently. The first codified set of immigration laws that specified the manner in which travelers to America could gain citizenship was the Naturalization Act of 1790, which prohibited any people of color. In recent immigration governing developments, the bureau of Immigration and Nationalization Services (INS), which rose to national prominence in the wake of the Elian Gonzalez trial, was incorporated by the Department of Homeland Security in March of 2003.
Immigration law and the review of a visa for work or travel come into play when an candidate for immigration crosses a border or otherwise secures passage through a port of entry. However, the possession of a visa does not guarantee acceptance into the country. Upon arrival, immigration officials must inspect the person and his or her documents for evidence of something amiss, and if something is found, the individual could be refused entry altogether.
As stated, immigration laws vary in different principalities. Be aware of all rules and restrictions before traveling and applying for immigration services.