The Norris–La Guardia Act (also known as the Anti-Injunction Bill) was a 1932 United States federal law that banned yellow-dog contracts, barred federal courts from issuing injunctions against nonviolent labor disputes, and created a positive right of noninterference by employers against workers joining trade unions. The common title followed from the names of the sponsors of the legislation: Senator George W. Norris of Nebraska and Representative Fiorello H. La Guardia of New York, both Republicans.
The Act stated that yellow-dog contracts, where a worker agreed as a condition of employment that he would not join a labor union, were unenforceable in federal court.
The Act established as United States law that employees should be free to form unions without employer interference, and also withdrew from the federal courts jurisdiction relative to the issuance of injunctions in nonviolent labor disputes. No federal court can offer jurisdiction. The three provisions include protecting worker's self-organization and liberty, removing jurisdiction from federal courts, and outlawing the "yellow dog" contract.
Section 13A of the act was fully applied by the Supreme Court of the United States in New Negro Alliance v. Sanitary Grocery Co., in which, in an opinion authored by Justice Owen Roberts, the Court held that the act meant to prohibit employers from proscribing the peaceful dissemination of information concerning the terms and conditions of employment by those involved in an active labor dispute, even when such dissemination occurs on employer property.