es.[4] Stressing the fact that this amendment, unlike the
cognate section of the Articles of Confederation, omitted the word
"expressly" as a qualification of the powers granted to the National
Government, Chief Justice Marshall declared that its effect was to leave
the question "whether the particular power which may become the subject
of contest has been delegated to the one government, or prohibited to
the other, to depend upon a fair construction of the whole
instrument."[5]

The Taxing Power

Not until after the Civil War was the idea that the reserved powers of
the States comprise an independent qualification of otherwise
constitutional acts of the Federal Government actually applied to
nullify, in part, an act of Congress. This result was first reached in a
tax case--Collector _v._ Day.[6] Holding that a national income tax, in
itself valid, could not be constitutionally levied upon the official
salaries of State officers, Justice Nelson made the sweeping statement
that "* * * the States within the limits of their powers not granted,
or, in the language of the Tenth Amendment, 'reserved,' are as
independent of the general government as that government within its
sphere is independent of the States."[7] In 1939, Collector _v._ Day was
expressly overruled.[8] Nevertheless, the problem of reconciling State
and national interests still confronts the Court occasionally, and was
elaborately considered in New York _v._ United States,[9] where, by a
vote of six-to-two, the Court upheld the right of the United States to
tax the sale of mineral waters taken from property owned by a State.
Speaking for four members of the Court, Chief Justice Stone justified
the tax on the ground that "The national taxing power would be unduly
curtailed if the State, by extending its activities, could withdraw from
it subjects of taxation traditionally within it."[10] Justices
Frankfurter and Rutledge found in the Tenth Amendment "* * * no
restriction upon Congress to include the States in levying a tax exacted
equally from private persons upon the same subject matter."[11] Justices
Douglas and Black dissented, saying: "If the power of the federal
government to tax the States is conceded, the reserved power of the
States guaranteed by the Tenth Amendment does not give them the
independence which they have always been assumed to have."[12]

The Commerce Power

A year before Collector _v._ Day was decided, the Court held invalid,
exc