The Supreme Court of the United States has original jurisdiction in a small class of cases described in Article III, section 2, of the United States Constitution and further delineated by statute. Authority The relevant constitutional clause states: Certain cases that have not been considered by a lower court may be heard by the Supreme Court in the first instance under what is termed original jurisdiction. The Supreme Court's authority in this respect is derived from Article III of the Constitution, which states that the Supreme Court shall have original jurisdiction "in all cases affecting ambassadors, other public ministers and consuls, and those in which a state shall be party." The original jurisdiction of the court is set forth in . This statute provides that lower federal courts may also hear cases where the Supreme Court has original jurisdiction, with the exception of disputes between two or more states. When a case is between two or more states, the Supreme Court holds both original and exclusive jurisdiction, and no lower court may hear such cases. In one of its earliest cases, Chisholm v. Georgia, the court found this jurisdiction to be self-executing, so that no further congressional action was required to permit the court to exercise it. The constitutional grant of original jurisdiction to the Supreme Court cannot be expanded by statute. In the case of Marbury v. Madison, the newly elected President, Thomas Jefferson, ordered his acting Secretary of State not to deliver commissions for appointments that had been made by his predecessor, John Adams. One of these appointees, William Marbury, filed a petition for a writ of mandamus directly in the Supreme Court, on the jurisdictional grounds that the Judiciary Act of 1789 stated that the Supreme Court "shall have power to issue writs of prohibition to the district courts [...] and writs of mandamus [...] to any courts appointed, or persons holding office, under the authority of the United States". The court, in its first exercise of judicial review over a statute enacted by Congress, held that this grant of power to the Supreme Court was beyond what the Constitution permitted, and that this language was therefore invalid as unconstitutional. Cases The number of cases heard pursuant to the court's original jurisdiction "has always been a minute portion of its overall caseload", generally including only one or two such cases per term. Most of these cases involve