Separation of powers under the United States Constitution
Where Congress does not make great and sweeping delegations of its authority, the Supreme Court has been less stringent. One of the earliest cases involving the exact limits of non-delegation was Wayman v. Southard 23 U.S. (10 Wet.) 1, 42 (1825). Congress had delegated to the courts the power to prescribe judicial procedure; it was contended that Congress had thereby unconstitutionally clothed the judiciary with legislative powers. While Chief Justice John Marshall conceded that the determination of rules of procedure was a legislative function, he distinguished between "important" subjects and mere details. Marshall wrote that "a general provision may be made, and power given to those who are to act under such general provisions, to fill up the details."

Q: Who was Chief Justice of the Supreme Court when Wayman v. Southard reached the Supreme Court?
John Marshall