In recent years, some scholars, legislators, and others have proposed to reexamine and potentially reinterpret the U.S. Constitution's Citizenship Clause to change and limit the current rule of conferring U.S. citizenship at birth to any person born in the United States, or "birthright citizenship." The Citizenship Clause is the first clause of the Fourteenth Amendment, and states: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside…." The policy debates on the topic of birthright citizenship are far-ranging, driven by concerns regarding unauthorized immigration, global antiterrorism efforts, reports of "birth tourism," and congressional redistricting, among other issues. The legal debates, however, center squarely on the six words in the middle of the Citizenship Clause: "and subject to the jurisdiction thereof." The Citizenship Clause has conventionally been taken to require U.S. citizenship generally to be accorded automatically to any child born within the United States, regardless of the citizenship or status of the child's parents. The "subject to the jurisdiction thereof" language has been interpreted to impose limited exceptions, such as for children of diplomats and foreign ministers (who are accorded immunity from U.S. law). This interpretation flows from the English common law doctrine of jus soli ("right of soil"), under which a person's nationality at birth is determined by the territory within which the person was born. The alternative doctrine of jus sanguinis ("right of blood"), which determines a person's nationality by descent, is now the more common general system outside of North and South America. However, each system's adherents have incorporated some elements of the other, with few purely adopting one or the other. The jus soli interpretation of the Citizenship Clause is recognized in a number of judicial decisions; however, arguably, no case has ever directly held whether the Citizenship Clause extends to children of aliens who are present in the United States unlawfully. The factual scenarios of the key cases interpreting the Citizenship Clause, Elk v. Wilkins (1884) and United States v. Wong Kim Ark (1898), involved Native Americans and children of domiciled resident aliens, respectively. Elk found that members of Indian tribes were not granted U.S. citizenship by the Fourteenth Amendment (a situation which was eventually remedied by statute ), while Wong Kim Ark found that the child of Chinese citizens residing in San Francisco had become a U.S. citizen at the time of his birth and therefore was not subject to the Chinese Exclusion Acts of the time. Some scholarship in the past few decades has argued that the phrase "and subject to the jurisdiction thereof" in the Citizenship Clause was in fact intended by the framers of the Fourteenth Amendment to include only those children born to lawfully present or lawfully resident aliens, and not children of unauthorized or nonimmigrant aliens. These arguments have been embraced by some legislators, who have introduced bills since the early 1990s seeking to change the jus soli rule in various ways. Many of these bills target Section 301 of the Immigration and Nationality Act (INA), which tracks the language of the Citizenship Clause and states: "The following shall be nationals and citizens of the United States at birth: (a) a person born in the United States, and subject to the jurisdiction thereof…." Any statute reinterpreting the Citizenship Clause to exclude children of certain aliens would face judicial review by federal courts. Because of the core constitutional principles involved, it seems probable that any case on such a statute could reach the Supreme Court. The Court could find such a statute constitutional if it interpreted the "subject to the jurisdiction" language of the Citizenship Clause to exclude the children of certain aliens from the scope of the Clause's protection. To uphold a statute limiting birthright citizenship, it would also appear that the Court would have to find either (1) that the discussion in Wong Kim Ark apparently supporting the conventional interpretation of birthright citizenship was mere dicta, not binding precedent, and the case's holding was limited to the facts of that case; or (2) that Wong Kim Ark incorrectly interpreted the Citizenship Clause, at least in some respects, and should be overruled. If a statute could not change the meaning of the Citizenship Clause, then a constitutional amendment, as some have proposed, would have the power to do so. Proponents and opponents of the current birthright citizenship rule have marshalled a variety of arguments and historical records on all of these points. This report first sets the stage for analyzing the modern debates by providing a brief historical review of U.S. citizenship from the time of the founding through the Civil Rights Act of 1866 and the Citizenship Clause of the Fourteenth Amendment of 1868. It then describes the primary Supreme Court decisions analyzing the scope of the Citizenship Clause, as well as subsequent decisions generally reflecting the conventional understanding of birthright citizenship. This report then presents an overview of the main legal arguments for and against reassessing the scope of the Citizenship Clause, building on the history and judicial precedent described in previous sections. In light of the various bills that have been proposed to modify birthright citizenship, this report closes by discussing the primary legal considerations that would determine whether any congressional action to restrict birthright citizenship of U.S.-born children of alien parents without constitutional amendment could be upheld. The original framers of the U.S. Constitution referenced, but did not define, national citizenship. The Constitution required that a person have been a citizen of the United States for seven years to be a Representative and for nine years to be a Senator, and that a person be a natural-born citizen or a citizen at the time of the adoption of the Constitution in order to be eligible to be President. It also gave Congress the power to establish a uniform rule of naturalization, but naturalization refers to the manner in which a non-citizen acquires citizenship, rather than citizenship by birth. Nor did the Naturalization Act of 1790 or subsequent acts until the Civil Rights Act of 1866 define citizenship by birth within the United States. In the absence of any statement in the Constitution or federal statutes that U.S. citizenship was acquired by right of birth in the United States, citizenship at birth generally was construed in the context of the English common law. As noted by the Supreme Court, "[t]he interpretation of the Constitution of the United States is necessarily influenced by the fact that its provisions are framed in the language of the English common law, and are to be read in the light of its history." For example, in an 1824 inheritance case, the Supreme Court proceeded on the assumption that three girls born in the United States were citizens, although their father was an Irish citizen who never naturalized. In 1830, the Supreme Court held that the law of England as to citizenship at birth was the law of the English colonies, and that a person born in New York after the Declaration of Independence on July 4, 1776 was a citizen of the United States, unless he was born in British-occupied territory, left for England as a minor, and did not elect to affirm his U.S. citizenship within a reasonable time after attaining his majority. In another early case more directly on point, Lynch v. Clarke , a New York court held in 1844 that Julia Lynch, born to Irish aliens while they were temporarily sojourning in New York, was a U.S. citizen. In determining the appropriate national law to apply, the Lynch court looked to the traditional English common law doctrine of jus soli , holding that by the "law of the United States, every person born within the dominions and allegiance of the United States, whatever were the situation of his parents, is a natural born citizen." These birthright citizenship principles were not extended to slaves, or generally to Native Americans. Moreover, in the infamous 1857 case of Dred S cott v. Sandford , Supreme Court Chief Justice Roger B. Taney wrote that the Constitution "point[ed] directly and specifically to the negro race as a separate class of persons, and show[ed] clearly that they were not regarded as a portion of the people or citizens of the Government then formed," and held that the Constitution precluded both Congress and states from granting citizenship to descendants of slaves or people of African descent generally. As such, the Dred Scott decision applied a rigid racial limitation on the jus soli doctrine. Following the Civil War, Congress passed the Civil Rights Act of 1866. The first section of that act repealed Dred Scott . It provided "[t]hat all persons born in the United States and not subject to any foreign power, excluding Indians not taxed, are hereby declared to be citizens of the United States…." Prior to passage of the act, Congress debated its effects on citizenship, particularly the language "not subject to any foreign power, excluding Indians not taxed." Senator Lyman Trumbull, a lead sponsor, introduced language similar to the above but omitting the exclusion for "Indians not taxed" on January 30, 1866. Senator Trumbull explained that "[o]ur dealings with the Indians are with them as foreigners, as separate nations," and in response to an inquiry from Senator Edgar Cowen whether the provision would "have the effect of naturalizing the children of Chinese and Gypsies born in this country," responded: "Undoubtedly." Notably, Senator Trumbull and Senator Cowen agreed that "the children of German parents" were citizens under what was then the current law, and disagreed over the effects of race, rather than alien status of the parents. However, in other statements on the citizenship provision, Senator Trumbull discussed the requirements of citizenship to be enshrined by the provision in terms of "owing allegiance" to the United States, or similar conditions seemingly additional to geographic presence.