Congress had previously passed laws regulating the
hunting of migratory waterfowl on the basis that such birds naturally migrated across state and international borders freely, and hence the regulation of the harvest of such birds could not realistically be considered to be province solely of individual states or groups of states. However, several states objected to this theory, and twice successfully sued to have such laws declared
unconstitutional, on the premise that the U.S. Constitution gave Congress no enumerated power to regulate migratory bird hunting, thereby leaving the matter to states pursuant to the Tenth Amendment. Disgruntled with these rulings, Congress then empowered the
State Department to negotiate with the
United Kingdom—which at the time still largely handled the foreign relations of
Canada—a
treaty pertaining to this issue. The treaty was subsequently
ratified and came into force, requiring the federal government to enact laws regulating the capturing, killing, or selling of protected migratory birds, an obligation that it fulfilled in the
Migratory Bird Treaty Act of 1918. The
state of
Missouri requested that
U.S. Game Warden Ray Holland be
enjoined from implementing the Act, arguing that it was "an unconstitutional interference with the rights reserved to the States by the Tenth Amendment, and [...] the acts of the defendant [...] invade the sovereign right of the State and contravene its will manifested in statutes." The state also warned that permitting the federal government to regulate birds could set a dangerous precedent for government to broaden its power over other domains for which it had no enumerated constitutional power. ==Judgment==