The Supreme Court created a new federal power to act in accordance with treaties.
The state of Missouri tried to prevent the enforcement of a statute resulting from the Migratory Bird Treaty Act of 1918, charging that the law intruded on the rights reserved to the states under the Tenth Amendment. By a 7-2 vote, the Supreme Court upheld the federal law enacted in compliance with the migratory bird treaty. An earlier decision not involving a treaty had held that states owned the birds within their borders, but in his opinion for the Court, Justice Oliver Wendell Holmes
Foreign affairs and foreign policy
States’ rights and state sovereignty