John Marshall, now chief justice of the Supreme Court, noted that Marbury was entitled to his commission, as he had been appointed by the president, confirmed by the Senate and otherwise qualified for the position. The Court also determined that Secretary of State James Madison wrongfully withheld Marbury’s commission from him.

However, Marshall also ruled that Marbury’s suit must fail because Section 13 of the Judiciary Act of 1789, which authorized the Court to issue a writ of mandamus, was unconstitutional. Marshall reasoned that Section 13 conflicted with Article III of the U.S. Constitution, which provided that the Supreme Court did not have original jurisdiction of Marbury’s case, only appellate jurisdiction. In other words, Marshall reasoned that Section 13 was unconstitutional because it attempted to confer original jurisdiction to litigants like William Marbury, but the Constitution provided that the Court only had appellate jurisdiction, meaning the suit had to be filed in the lower courts. Marshall explained that “the jurisdiction had to be appellate, not original.”