In short, the American people were presented, overnight as it were, with
a new doctrine of Natural Law. Encouraged by certain dicta of dissenting
Justices of the Supreme Court, a growing procession of high State
courts--those of New York, Pennsylvania, Illinois, and Massachusetts,
leading the way--now began infiltrating the due process clauses and
especially the word "liberty" thereof, of their several State
constitutions with the new revelation. The product of these activities
was the doctrine of freedom of contract, the substantial purport of
which was that any legislation which restricted the liberty of male
persons twenty-one years of age, whether they were employers or
employees, in the making of business contracts, far from being
presumptively constitutional, must be justified by well known facts of
which the court was entitled to take judicial notice; otherwise it fell
under the ban of the due process clause.[69]

At last, in 1898, the Supreme Court at Washington, following some
tentative gestures in that direction, accepted the new dispensation
outright. In Smyth _v._ Ames decided that year, partially overturning
Munn _v._ Illinois, it gave notice of its intention to review in detail
the "reasonableness" of railway rates set by State authority and in
Holden _v._ Hardy it ratified, at the same term, the doctrine of freedom
of contract.[70] The result of the two holdings for the Court's
constitutional jurisdiction is roughly indicated by the fact that
whereas it had decided 134 cases under the Amendment during the thirty
preceding years, in the ensuing thirteen years it decided 430 such
cases.[71]

For more than a generation now the Court became the ultimate guardian,
in the name of the Constitutional Document, of the _laissez-faire_
conception of the proper relation of Government to Private Enterprise, a