The best-known, and most often-cited, power of the U.S. Supreme Court is the power of judicial review. This power, established in 1803 by a Supreme Court ruling, allows the Court to rule on the Constitutionality of an executive order or congressional legislation.
With the passage of the 14th Amendment in 1869, judicial review applied to all laws within the United States, giving the Court the power to strike down laws and legislation which violated the Constitution. This included Federal and state-level laws, passed either through Congress or through popular vote.
In addition, as the highest court in the land, the Supreme Court sets legal precedence for all other courts, both criminal and civil. This also empowers the Court to prevent a popular majority from passing laws, even through a general election process, which limit or strip the rights of any group of American citizens. The use of judicial review has resulted in many significant victories for civil rights groups.
Less well-known are the powers invested in the Supreme Court by Article 3 of the Constitution, which establishes the Court's jurisdiction. The Court holds original jurisdiction over conflicts between two or more states, as well as jurisdiction over cases involving U.S. Ambassadors or ministers, and all cases involving maritime travel.