The size of the Court is not specified; the Constitution leaves it to Congress to set the number of justices.

were decided the Court comprised these nine members: Levi Woodbury In Cooley v. Board of Wardens, 53 U.S. (12 How.)

299 (1852), the Supreme Court held that a Pennsylvania law requiring all ships entering or leaving the Port of Philadelphia to hire a local river pilot did not violate the Commerce Clause of the Constitution.

The Court decided that the constitutional grant to Congress of power to regulate interstate commerce did not deprive the states of power to regulate maritime pilots; although Congress had legislated on the subject, its legislation showed an intention not to preempt the entire topic.

The ruling, however, "empowered the slave states to interfere with interstate commerce to protect slavery.