Which 1789 U.S. law established the federal judiciary, including the first lower federal courts?

The Judiciary Act of 1789 established the federal judiciary, including the first lower federal courts beneath the Supreme Court.

Congress passed the law during the first session of the First Congress, and President George Washington signed it on September 24, 1789. The Constitution had authorized a federal judicial branch but left its detailed structure to Congress.

The act organized federal district and circuit courts, set the Supreme Court’s original membership at six justices, and created the offices of U.S. attorney and U.S. marshal in each judicial district. It initially established thirteen districts across eleven states.

The law also shaped the Supreme Court’s jurisdiction. One provision was later partly invalidated in Marbury v. Madison, when the Court ruled that Congress had exceeded its constitutional authority in granting certain original-jurisdiction powers.