The Judiciary Act of 1789, passed on September 24 of that year, established the Judicial Branch of government, with a Supreme Court and rudimentary federal court system. This was the first legislation passed by the new Congress.
The Act created thirteen District Courts, which heard small civil suits and minor crimes, within three Federal Circuits. Three Circuit Courts had original jurisdiction over serious federal criminal cases, and appellate jurisdiction over cases heard in the District Courts. The six US Supreme Court justices were responsible for "riding circuit" twice a year, traveling in pairs, and hearing cases as appellate judges. Congress believed this would help the Supreme Court justices stay in touch with local concerns.
Section 1 of the Act declared "the supreme court of the United States shall consist of a chief justice and five associate justices, any four of whom shall be a quorum, and shall hold annually at the seat of government two sessions, the one commencing the first Monday of February, and the other the first Monday of August. That the associate justices shall have precedence according to the date of their commissions, or when the commissions of two or more of them bear date on the same day, according to their respective ages."
Section 13 of the Judiciary Act was a topic of controversy in Marbury v. Madison, (1803), when Chief Justice Marshall decided that portion of the legislation was unconstitutional because Congress had overstepped its authority by authorizing the Court to issue writs of mandamus to US government officials, which Marshall interpreted as being in contradiction with the Constitution.