The Judiciary Act of 1801 expanded the Federal Court System.
Within the twelve years since the federal judiciary was established, Congress approved a reorganization of the nation's court system, resulting to the significant expansion of the federal jurisdiction.
The Judiciary Act of 1801 decreased the number of justices in the Supreme Court from six to five justices and eliminated their duties of doing circuits around the country. Instead, the Act created sixteen judgeships for the six judicial circuits. The US circuit courts, where new judges will preside, gained jurisdiction over all cases arising under the Constitution and acts of the United States.