al
systems in the world.

At the time of the adoption of the Constitution this division of
jurisdiction was quite feasible, for, geographically, the various States
were widely separated, and the lack of economic contact made it easy for
each government to function without serious conflict. The framers,
however, did not sufficiently reckon with the mechanical changes in
society that were then beginning. They did not anticipate, and could not
have anticipated, the centripetal influences of steam and electricity
which have woven the American people into an indissoluble unit for
commercial and many other purposes. As a result many laws of the Federal
Government, in their incidences in this complex age, directly impinge
upon rights of the State governments, and _vice versa_, and the
practical application of the Constitution has required a very subtle
adaptation of a form of government which was enacted in a primitive age
to a form of government of a complex age.

Take, for example, the power over commerce. According to the
Constitution, the Federal Government had plenary power over foreign
commerce and commerce _between_ the States, but the power over commerce
_within_ a State was reserved to State governments. This presupposed the
power of Government to divide commerce into two water-tight
compartments, or, at least, to regard the two spheres of power as
parallel lines that would never meet; whereas with the coming of the
railroad, steamship and the telegraph commerce has become so unified
that the parallel lines have become lines of interlacing zigzags. To
adapt the commerce clause of the Constitution to these changed
conditions has required, in the highest degree, the constructive genius
of the Supreme Court of the United States, and, in a series of very
remarkable decisions, which are contained in 256 volumes of the official
reports, that great tribunal has tried to draw a line between
inter-State and domestic commerce as nearly to the original plans of the
framers as it was possible; but obviously there has been so much
adaptation to make this possible that if Washington, Franklin, Madison
and Hamilton could revisit the nation they created they would not
recognize their own handiwork.

For the same reason, the dual system of government has been profoundly
modified by the great elemental forces of our mechanical age, so that
the scales, which try to hold in nice equipoise the Federal Government
on the one hand and th