Takeaway
In short, this case holds that a valid treaty, and federal legislation necessary to implement it, may override state authority even where Congress could not regulate the same subject through ordinary legislation alone.
Missouri sued in equity to stop a federal game warden from enforcing the Migratory Bird Treaty Act of 1918 and regulations issued under it. The Act implemented a 1916 convention between the United States and Great Britain protecting migratory birds that traveled between the United States and Canada. The treaty responded to the birds' threatened extermination and required each nation to adopt protective measures, including closed hunting seasons.
Missouri argued that regulating the taking of wild birds within its borders was reserved to the States by the Tenth Amendment. It asserted both a sovereign interest in controlling wildlife and a pecuniary interest as owner of the birds within the State. A federal district court dismissed the bill, holding the Act constitutional. Missouri appealed directly to the Supreme Court.
Issue #1
Whether Missouri had a sufficient interest to bring a suit challenging federal enforcement of the Migratory Bird Treaty Act.
Holding
Yes. Missouri could sue to assert its alleged quasi-sovereign rights and its admitted pecuniary interest in the birds within its borders.
Reasoning
The federal government conceded that Missouri's asserted pecuniary interest was sufficient. The Court also explained that the suit was a reasonable and proper way for a State to assert the quasi-sovereign interests Missouri claimed were being invaded by federal action.
Issue #2
Whether the Tenth Amendment prevents the United States from making a treaty that addresses a subject otherwise within a State's regulatory authority.
Holding
No. The Tenth Amendment does not create the proposed limitation on the expressly delegated treaty power.
Reasoning
The Constitution expressly delegates the power to make treaties in Article II, and Article VI makes treaties made under the authority of the United States part of the supreme law of the land. Thus, the inquiry could not end with the Tenth Amendment's reservation of powers not delegated to the federal government.
Missouri's proposed rule was that a treaty could not accomplish what Congress could not accomplish through ordinary legislation alone. The Court rejected that rule. Statutes are supreme only when made pursuant to the Constitution, whereas treaties are declared supreme when made under the authority of the United States; the validity of the treaty power therefore cannot simply be measured by the limits on Congress's independent legislative power.
The Court acknowledged that the treaty power has constitutional limits, but held that those limits must be found through an analysis of the Constitution rather than through an implied, or 'invisible,' restriction derived from the Tenth Amendment. The migratory-bird treaty violated no express constitutional prohibition.
Justice Holmes emphasized that constitutional terms must be applied in light of the Nation's development and experience. Some matters of urgent national importance may require action by the United States in concert with another nation even when the States, acting separately, cannot effectively solve the problem.
Issue #3
Whether the Migratory Bird Treaty Act was a valid means of implementing the treaty.
Holding
Yes. Because the treaty was valid, Congress could enact the Act as a necessary and proper means of carrying it into effect.
Reasoning
The Court treated the statute's validity as following from the treaty's validity. Under the Necessary and Proper Clause, Congress may enact legislation needed to execute a valid federal power, including the treaty power.
Earlier lower-court decisions had invalidated a federal migratory-bird law enacted without a treaty. Those decisions did not control because the 1918 Act rested on a different constitutional source: it implemented an international agreement rather than standing solely on Congress's independent power to regulate birds within the States.
Issue #4
Whether Missouri's asserted ownership and regulatory authority over wild birds made the treaty and implementing statute unconstitutional as applied within the State.
Holding
No. Missouri's interest in birds temporarily present within its borders did not defeat the federal treaty power or the implementing statute.
Reasoning
The Court accepted that a State ordinarily may regulate the killing and sale of wild birds as against its own inhabitants. But that ordinary state authority is not exclusive when a valid federal power is exercised.
Missouri's claim of ownership was especially weak because wild birds are not possessed by anyone and move freely from State to State and across national borders. The State's practical claim was only that the birds happened to be within Missouri at a particular time and that, absent federal law, Missouri could regulate them.
Valid treaties can bind within the States and can override state rules governing matters ordinarily treated as private or local, including limitations periods, confiscation, escheat, and aspects of foreign-consular jurisdiction. The fact that federal officers enforce a treaty within a State therefore does not itself establish a Tenth Amendment violation.
The protection of migratory birds presented a national interest of the highest order. The birds' transitory character, their interstate and international migration, and the danger that they would be exterminated made reliance on separate state regulation inadequate. The Court concluded that the Constitution did not require the national government to remain inactive while a valuable food source and protectors of forests and crops were destroyed.