In law, common law is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions. The defining characteristic of “common law” is that it arises as precedent. In cases where the parties disagree on what the law is, a common law court looks to past precedential decisions of relevant courts, and synthesizes the principles of those past cases as applicable to the current facts. If a similar dispute has been resolved in the past, the court is usually bound to follow the reasoning used in the prior decision. If, however, the court finds that the current dispute is fundamentally distinct from all previous cases, and legislative statutes are either silent or ambiguous on the question, judges have the authority and duty to resolve the issue. The court states an opinion that gives reasons for the decision, and those reasons agglomerate with past decisions as precedent to bind future judges and litigants. Common law, as the body of law made by judges, stands in contrast to and on equal footing with statutes which are adopted through the legislative process, and regulations which are promulgated by the executive branch. Stare decisis, the principle that cases should be decided according to consistent principled rules so that similar facts will yield similar results, lies at the heart of all common law systems.
Marbury v. Madison, 5 U.S. 137 (1803), was a landmark U.S. Supreme Court case that established the principle of judicial review in the United States, meaning that American courts have the power to strike down laws and statutes that they find to violate the Constitution of the United States. Decided in 1803, Marbury remains the single most important decision in American constitutional law. The Court's landmark decision established that the U.S. Constitution is actual law, not just a statement of political principles and ideals, and helped define the boundary between the constitutionally separate executive and judicial branches of the federal government.
In the United States, a state court has jurisdiction over disputes with some connection to a U.S. state. State courts handle the vast majority of civil and criminal cases in the United States; the United States federal courts are far smaller in terms of both personnel and caseload, and handle different types of cases.
McCulloch v. Maryland, 17 U.S. 316 (1819), was a landmark U.S. Supreme Court decision that defined the scope of the U.S. Congress's legislative power and how it relates to the powers of American state legislatures. The dispute in McCulloch involved the legality of the national bank and a tax that the state of Maryland imposed on it. In its ruling, the Supreme Court established firstly that the "Necessary and Proper" Clause of the U.S. Constitution gives the U.S. federal government certain implied powers that are not explicitly enumerated in the Constitution, and secondly that the American federal government is supreme over the states, and so states' ability to interfere with the federal government is limited.
The Slaughter-House Cases, 83 U.S. 36 (1873), was a landmark U.S. Supreme Court decision that held that the Privileges or Immunities Clause of the Fourteenth Amendment to the U.S. Constitution only protects the legal rights that are associated with federal U.S. citizenship, not those that pertain to state citizenship. The decision consolidated two similar cases.
Griswold v. Connecticut, 381 U.S. 479 (1965), was a landmark decision of the US Supreme Court in which the Court ruled that the Constitution of the United States protects the liberty of married couples to buy and use contraceptives without government restriction. The case involved a Connecticut "Comstock law" that prohibited any person from using "any drug, medicinal article or instrument for the purpose of preventing conception." The court held that the statute was unconstitutional, and that "the clear effect of [the Connecticut law ...] is to deny disadvantaged citizens ... access to medical assistance and up-to-date information in respect to proper methods of birth control." By a vote of 7–2, the Supreme Court invalidated the law on the grounds that it violated the "right to marital privacy", establishing the basis for the right to privacy with respect to intimate practices. This and other cases view the right to privacy as a right to "protect[ion] from governmental intrusion".
United States v. Butler, 297 U.S. 1 (1936), is a U.S. Supreme Court case that held that the U.S. Congress has not only the power to lay taxes to the level necessary to carry out its other powers enumerated in Article I of the U.S. Constitution but also a broad authority to tax and spend for the "general welfare" of the United States. The decision itself concerned whether the processing taxes instituted by the 1933 Agricultural Adjustment Act were constitutional.
In common law legal systems original jurisdiction of a court is the power to hear a case for the first time, as opposed to appellate jurisdiction, when a higher court has the power to review a lower court's decision.
United States v. Carolene Products Company, 304 U.S. 144 (1938), was a case of the United States Supreme Court that upheld the federal government's power to prohibit filled milk from being shipped in interstate commerce. In his majority opinion for the Court, Associate Justice Harlan F. Stone wrote that economic regulations were "presumptively constitutional" under a deferential standard of review known as the "rational basis test".
Article I, Section 10, Clause 1 of the United States Constitution, known as the Contract Clause, imposes certain prohibitions on the states. These prohibitions are meant to protect individuals from intrusion by state governments and to keep the states from intruding on the enumerated powers of the U.S. federal government.
Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938), is a landmark decision by the Supreme Court of the United States in which the Court held that federal courts did not have the judicial power to create general federal common law when hearing state law claims under diversity jurisdiction. In reaching this holding, the Court overturned almost a century of federal civil procedure case law, and established the foundation of what remains the modern law of diversity jurisdiction as it applies to United States federal courts.
Federal common law is a term of United States law used to describe common law that is developed by the federal courts, instead of by the courts of the various states. The United States is the only country to combine the creation of common law doctrines with a complete federalism, wherein the national supreme court has virtually no power to review state court decisions to determine whether the state courts have followed state laws. The High Court of Australia is sometimes said to have federal common law, but because all state and territorial courts are directly appealable to the High Court, this is indistinguishable from a general common law. In contrast, the United States Supreme Court has effectively barred the creation of federal common law in areas traditionally under the authority of state courts. Nevertheless, there are several areas where federal common law continues to govern.
The Erie doctrine is a fundamental legal doctrine of civil procedure in the United States which mandates that a federal court called upon to resolve a dispute not directly implicating a federal question must apply state substantive law.
Younger v. Harris, 401 U.S. 37 (1971), was a case in which the United States Supreme Court held that United States federal courts were required to abstain from hearing any civil rights tort claims brought by a person who is currently being prosecuted for a matter arising from that claim.
Implied cause of action is a term used in United States statutory and constitutional law for circumstances when a court will determine that a law that creates rights also allows private parties to bring a lawsuit, even though no such remedy is explicitly provided for in the law. Implied causes of action arising under the Constitution of the United States are treated differently from those based on statutes.
Johnson v. Zerbst, 304 U.S. 458 (1938), was a United States Supreme Court case, in which the petitioner, Johnson, had been convicted in federal court of feloniously possessing, uttering, and passing counterfeit money in a trial where he had not been represented by an attorney but instead by himself. Johnson filed for habeas corpus relief, claiming that his Sixth Amendment right to counsel had been violated, but he was denied by both a federal district court and the court of appeals.
Richardson v. Ramirez, 418 U.S. 24 (1974), is a decision by the Supreme Court of the United States that held that convicted felons could be barred from voting without violating the Fourteenth Amendment to the Constitution. Such felony disenfranchisement is practiced in a number of U.S. states.
Virginia v. Maryland, 540 U.S. 56 (2003), is a case in which the Supreme Court of the United States settled a dispute between the Commonwealth of Virginia and the State of Maryland regarding Virginia's riparian rights to the Potomac River. The Supreme Court held in a 7—2 decision that Maryland has no legal authority to regulate or prohibit Virginia and its political subdivisions from building and improving structures in the river and from drawing water from the river. The decision drew heavily on the Maryland–Virginia Compact of 1785, an agreement between the two states concerning navigational and riparian water rights along the Potomac River.
Texas v. New Mexico and Colorado, 141-orig, ___ U.S. ___ (2018), was a Supreme Court case argued and decided during the 2017 term of the Supreme Court of the United States. The case involved an interstate dispute regarding New Mexico's compliance with the Rio Grande Compact of 1938, an agreement which established a plan for equitable apportionment of the water in the Rio Grande Basin among the states of Colorado, New Mexico, and Texas. The Court considered the question of whether the US federal government had a legal right to join litigation against New Mexico; the Court ruled that the federal government was within its rights when it did so.
Franchise Tax Board of California v. Hyatt, 587 U.S. ___ (2019), was a United States Supreme Court case that determined that unless they consent, states have sovereign immunity from private suits filed against them in the courts of another state. The 5–4 decision overturned precedent set in a 1979 Supreme Court case, Nevada v. Hall. This was the third time that the litigants had presented their case to the Court, as the Court had already ruled on the issue in 2003 and 2016.
