Case law, also used interchangeably withcommon law, is alaw that is based onprecedents, that is thejudicial decisions from previous cases, rather than law based onconstitutions,statutes, orregulations. Case law uses the detailed facts of alegal case that have been resolved bycourts or similartribunals. These past decisions are called "case law", or precedent.Stare decisis—a Latin phrase meaning "let the decision stand"—is the principle by which judges are bound to such past decisions, drawing on established judicial authority to formulate their positions. (Full article...)

United States v. Wong Kim Ark, 169 U.S. 649 (1898), is alandmark decision of theU.S. Supreme Court which held that "a child born in the United States, of parents of Chinese descent, who, at the time of his birth, are subjects of the Emperor of China, but have a permanentdomicile and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the Emperor of China", automatically became aU.S. citizen at birth.Wong Kim Ark was the first Supreme Court case to decide on the status of children born in the United States to alien parents. This decision established an importantprecedent in its interpretation of theCitizenship Clause of theFourteenth Amendment to the Constitution.
Wong Kim Ark, who was born inSan Francisco in 1873, had been denied re-entry to the United States after a trip abroad, under theChinese Exclusion Act, a law banning virtually all Chinese immigration and prohibiting Chinese immigrants from becomingnaturalized U.S. citizens. He challenged the government's refusal to recognize his citizenship, and the Supreme Court ruled in his favor, holding that the Citizenship Clause should be interpreted "in light of the common law". The case highlighted disagreements over the precise meaning of one phrase in the Citizenship Clause—namely, the provision that a person born in the United States who is "subject to the jurisdiction thereof" acquires automatic citizenship.
The Supreme Court's majority concluded that this phrase referred to being required to obey U.S. law; on this basis, they interpreted the Citizenship Clause of the Fourteenth Amendment to grant citizenship to children born in the United States, with only a limited set of exceptions based onEnglish common law. The Court held that being born to alien parents was not one of those exceptions. The court's dissenters argued that being subject to the jurisdiction of the United States meant not being subject to any foreign power—that is, not being claimed as a citizen by another country viajus sanguinis (inheriting citizenship from a parent)—an interpretation which, in the minority's view, would have excluded "the children of foreigners, happening to be born to them while passing through the country". (Full article...)