The Constitution mentions only one court by name: the Supreme Court. Article III leaves everything else to Congress, granting power to "ordain and establish" whatever lower courts the country needs. The first Congress used that authority immediately, passing the Judiciary Act of 1789 to create 13 district courts and three circuit courts staffed partly by Supreme Court justices riding circuit. Today that system has grown to 94 federal district courts and 13 courts of appeals, but Congress could restructure or even abolish them. That power gives lawmakers enormous leverage over the judiciary. Congress decides how many judges sit on each court, what cases they can hear, and how their jurisdictions are drawn. When lawmakers created the Court of Appeals for the Federal Circuit in 1982, they consolidated patent and trade cases into one specialized court. The fact that lower federal courts exist only at Congress's discretion -- not by constitutional command -- means the shape of American justice depends as much on legislation as on the Constitution itself.