美國早年承襲英國的自然法傳統，只要在美國領土出生，就自動取得美國國籍，這就是出生公民權（birthright citizenship）。然而在以白人為主的社會下，美國的黑人與印地安人被排除在出生公民權之外。本文的主旨在呈現修憲加入出身公民權條款與其他曲折的過程，出生公民權的適用範圍逐漸擴大，包括了黑人、印地安人與華人。近年來，因經濟因素，美國社會保守意識提升，反移民的提議增多，承襲英國自然法的出生公民權也受到挑戰，然而考慮到社會穩定與美國傳統因素，以保守派大法官居多的最高法院目前不致於限縮出生公民權的適用範圍。

Those who were born in the territory of United State are American citizens (birthright citizenship). This is American legal tradition inherited from British Natural Law principle. However in White people dominating society, birthright citizenship did not include Black and Indians. The purpose of the paper is to demonstrate that through birthright citizenship clause of US Constitutional amendment the minorities (Black, Indians and Chinese) experienced difficult historical steps and finally were accepted as US citizens. These several years, due to economic down turn, conservative thought is prevalent; anti-immigration initiatives increase than before. One of them is to limit birthright citizenship which comes from natural law of Britain to only American and legal alien residents; undocumented (or illegal) alien residents are excluded. However, considering social stability and American tradition, the possibility to limit birthright citizenship target is low even conservative Justices are majority in the Supreme Court.