postal power
Postal power is granted to Congress through the U.S. Constitution. Under Article I, Section 8, Clause 7, Congress has the sole and exclusive power to establish post offices and post roads. This power includes the power to ensure the safe and speedy transit and prompt delivery of mail.
In M’Culloch v. Maryland, Chief Justice Marshall noted that under the necessary and proper clause, the postal power included various implied powers, such as the power and duty to carry mail along the post road, and the right to punish those who would steal or rob it. This includes robbing the mail itself, robbing mail carriers, stealing mail, and defrauding others through the mail.
However, the postal power is subject to the constitutional limitations of the Bill of Rights, particularly the First Amendment, as shown in Lamont v. Postmaster General, where an act of Congress preventing the delivery of “communist political propaganda” was deemed unconstitutional. Despite this limitation, exceptions have been made for mailing materials that promote obscenity. The Supreme Court held in Roth v. U.S. that the federal obscenity statute punishing the use of mail to distribute obscene matter was a proper use of the postal power. The decision in Miller v. California later superseded this decision, holding that obscene materials as a whole do not have First Amendment protection.
The postal system is generally free from regulation by state laws; however, states can regulate actions that may incidentally involve the use of mail, such as the distribution of controlled substances, or the prevention of fraud and other deceptive trade practices.
In 1970, Congress adopted the Postal Reorganization Act, which established the United States Postal Service (USPS) and delegated power to the Postmaster General. The Postmaster General has substantial decision-making capability and can make subsidiary rules and regulations governing mail.
See: Congressional power, U.S. Constitution Annotated Article I S8 C7.1 Historical Background on Postal Power, U.S. Constitution Annotated Article I S8 C7 1.1 Postal Power: Overview, U.S. Constitution Annotated Article VI C2 2.1 The Articles of Confederation and Supremacy of Federal Law.
[Last reviewed in June of 2025 by the Wex Definitions Team]
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