very rapidly decreasing in the North and not in the South, and that the
gradual abolition of slavery was proceeding in the North alone, and that
with increasing rapidity. But there was no positive evidence that the
South was bulwarked in favor of slavery; there was no certainty but that
the South would in its turn and in due time come to the point which the
North had already reached, and begin its own abolition of slavery. The
language of Washington, Jefferson, Madison, Henry, and Mason, in regard
to the evils or the wickedness of the system of slavery, was too strong
to be heard with patience in the South of after years; and in this
section it seems to have been true, that those who thought at all upon
the subject hoped sincerely for the gradual abolition of slavery in
the South. The hope, indeed, was rather a sentiment than a purpose, but
there seems to have been no good reason, before 1793, why the sentiment
should not finally develop into a purpose.

All this was permanently changed, and the slavery policy of the South
was made antagonistic to, and not merely divergent from, that of the
North, by the invention of Whitney's saw gin for cleansing cotton
in 1793. It had been known, before that year, that cotton could be
cultivated in the South, but its cultivation was made unprofitable, and
checked by the labor required to separate the seeds from the cotton.
Whitney's invention increased the efficiency of this labor hundreds of
times, and it became evident at once that the South enjoyed a practical
monopoly of the production of cotton. The effect on the slavery policy
of the South was immediate and unhappy. Since 1865, it has been found
that the cotton monopoly of the South is even more complete under a
free than under a slave labor system, but mere theory could never have
convinced the Southern people that such would be the case. Their whole
prosperity hinged on one product; they began its cultivation under slave
labor; and the belief that labor and prosperity were equally dependent