Substantive due process is a principle in United States constitutional law that allows courts to establish and protect certain fundamental rights from government interference, even if they are unenumerated elsewhere in the U.S. Constitution. Courts have asserted that such protections come from the due process clauses of the Fifth and Fourteenth amendments to the U.S. Constitution, which prohibit the federal and state governments, respectively, from depriving any person of "life, liberty, or property, without due process of law". Substantive due process demarks the line between those acts that courts hold to be subject to government regulation or legislation and those that courts place beyond the reach of governmental interference. Whether the Fifth or Fourteenth Amendments were intended to serve that function continues to be a matter of scholarly as well as judicial discussion and dissent. In recent opinions, Justice Clarence Thomas has called on the Supreme Court to reconsider all of its rulings that were based on substantive due process.
In the law of the United States, diversity jurisdiction is a form of subject-matter jurisdiction that gives U.S. federal courts the power to hear lawsuits that do not involve a federal question. For a U.S. federal court to have diversity jurisdiction over a lawsuit, two conditions must be met. First, there must be "diversity of citizenship" between the parties, meaning the plaintiffs must be citizens of different U.S. states than the defendants. Second, the lawsuit's "amount in controversy" must be more than $75,000. If a lawsuit does not meet these two conditions, U.S. federal courts will normally lack the power to hear it unless it involves a federal question, and the lawsuit would need to be heard in state court instead.
Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938), was a landmark U.S. Supreme Court decision in which the Court held that there is no general American federal common law and that U.S. federal courts must apply state law, not federal law, to lawsuits between parties from different states that do not involve federal questions. 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.
Sampson v. Channell, 110 F.2d 754, was a United States Court of Appeals decision interpreting the application of the Erie doctrine where diversity jurisdiction is invoked in a choice of law situation, where a court in one state may be called upon to apply the laws of another state.
England v. Louisiana State Board of Medical Examiners, 375 U.S. 411 (1964), was a United States Supreme Court decision that refined the procedures for U.S. federal courts to abstain from deciding issues of state law, pursuant to the doctrine set forth in Railroad Commission v. Pullman Co., 312 U.S. 496 (1941).
In conflict of laws, renvoi is a subset of the choice of law rules and it may be applied whenever a forum court is directed to consider the law of another state.
In all lawsuits involving conflict of laws, questions of procedure as opposed to substance are always determined by the lex fori, i.e. the law of the state in which the case is being litigated.
Conflict of laws in the United States is the field of procedural law dealing with choice of law rules when a legal action implicates the substantive laws of more than one jurisdiction and a court must determine which law is most appropriate to resolve the action. In the United States, the rules governing these matters have diverged from the traditional rules applied internationally. The outcome of this process may require a court in one jurisdiction to apply the law of a different jurisdiction.
Byrd v. Blue Ridge Rural Electric Cooperative, Inc., 356 U.S. 525 (1958), decided on May 19, 1958, was a decision by the Supreme Court of the United States that refined the doctrine regarding in what instances courts were required to follow state law.
Hanna v. Plumer, 380 U.S. 460 (1965), was a decision by the Supreme Court of the United States, in which the Court further refined the Erie doctrine regarding when and by what means federal courts are obliged to apply state law in cases brought under diversity jurisdiction. The question in the instant case was whether Federal Rules of Civil Procedure governing service of process should yield to state rules governing the service of process in diversity cases. The Court ruled that under the facts of this case, federal courts shall apply the federal rule. The decision was drafted by John Hart Ely, who was then a law clerk for Earl Warren.
Sibbach v. Wilson & Co., 312 U.S. 1 (1941), was a decision by the United States Supreme Court in which the Court held that under American law important and substantial procedures are not substantive, rather they are still considered procedural, and federal law applies.
Sosa v. Alvarez-Machain, 542 U.S. 692 (2004), was a United States Supreme Court case involving the Alien Tort Statute and the Federal Tort Claims Act. Many ATS claims were filed after the Second Circuit ruling in Filártiga v. Peña-Irala created a new common law cause of action for torture under the ATS: “For purposes of civil liability, the torturer has become—like the pirate and slave trader before him—hostis humani generis, an enemy of all mankind.” The Court in Sosa does not find there is a similar cause of action for arbitrary arrest and detention. They wrote that finding new common law causes of action based on international norms would require "a substantial element of discretionary judgment", and explain that the role of common law has changed since ATS was enacted meaning the Court will "look for legislative guidance before exercising innovative authority over substantive law".
Walker v. Armco Steel Corp., 446 U.S. 740 (1980), was a decision by the Supreme Court of the United States in which the Court further refined the test for determining whether federal courts sitting in diversity must apply state law as opposed to federal law. The question in Walker is whether in a diversity action the federal court should follow state law or, alternatively, Rule 3 of the Federal Rules of Civil Procedure in determining when an action is commenced for the purpose of tolling the state statute of limitations (SOL). The Court found no such conflict because a court’s refusal to apply the federal rule at issue would not in fact thwart some purpose the federal rule was intended to achieve. Favored treatment for federal procedural rules under the Rules Enabling Act is only appropriate when a rule is in fact applicable.
Gasperini v. Center for Humanities, 518 U.S. 415 (1996), was a decision by the Supreme Court of the United States in which the Court further refined the Erie doctrine regarding when and how federal courts are to apply state law in cases brought under diversity jurisdiction. The Court held that the New York state rule applied.
Southland Corp. v. Keating, 465 U.S. 1 (1984), is a United States Supreme Court decision concerning arbitration. It was originally brought by 7-Eleven franchisees in California state courts, alleging breach of contract by the chain's then parent corporation. Southland pointed to the arbitration clauses in their franchise agreements and said it required disputes to be resolved that way; the franchisees cited state franchising law voiding any clause in an agreement that required franchisees to waive their rights under that law. A 7-2 majority held that the Federal Arbitration Act (FAA) applied to contracts executed under state law.
Sun Oil Co. v. Wortman, 486 U.S. 717 (1988), was a conflict of laws case decided by the United States Supreme Court.
Evans v. Eaton, 20 U.S. 356 (1822), was a United States Supreme Court case in which the Court held, chiefly, that a patent on an improved machine must clearly describe how the machine differs from the prior art.
Logan v. Zimmerman Brush Co., 455 U.S. 422, is a unanimous 1982 decision of the U.S. Supreme Court concerning the Due Process Clause of the Fourteenth Amendment. The Court held that the petitioner was entitled to have his discrimination complaint adjudged by Illinois's Fair Employment Practices Commission (FEPC), which had dismissed it for its own failure to meet a deadline. The decision reversed the Illinois Supreme Court's holding to the contrary two years prior.
