This section of the Constitution says that the Supreme Court only has original jurisdiction over cases where a U.S. State is a party to a lawsuit or where a lawsuit involves foreign dignitaries. Neither of these categories covered Marbury's lawsuit, which was a dispute over a writ of mandamus for his justice of the peace commission. So, according to the Constitution, the Court could only have heard Marbury's case while exercising appellate jurisdiction over an appeal, not under original jurisdiction over a lawsuit directly filed with it, as Marbury had done.