ly designated as the _Mississippi Valley_,
estimated by Professor J. W. Foster of the Chicago University to contain
an area of two million four hundred and fifty-five thousand square
miles, equal to that of all Europe excepting Russia, Norway and Sweden.
Unlike the inland basin of Asia, in which the vast, mountain-girt Desert
of Gobi stretches out its seas of sand, stony, sterile and desolate, the
inland basin of America is its garden-spot and granary. Swept by the
vapor-bearing winds and rain-distilling clouds from the Gulf of Mexico,
and blessed with an excellent climate, it contains all the physical
elements of an empire within itself. Its position makes it the national
strong-hold, so that with military men it has grown into an adage,
"Whoever is master of the Mississippi is lord of the continent." It is
yet but half developed, but no far-seeing mind can form any estimate of
its future growth and opulence. "With a varied and splendid
entourage--an imperial cordon of States--nothing," says Dr. John W.
Draper of New York, "can prevent the Mississippi Valley from becoming in
less than three centuries the centre of human power." The only wall of
partition that shuts it off from the great marts of the world is formed
by the chain of the Alleghanies, which stretch along the Atlantic
seaboard, from south-west to north-east, for twelve hundred miles. This
natural barrier, with a mean altitude of two thousand feet, is destitute
of a central axis, and consists, as the two Rogerses, who have most
fully explored its ridges, showed, of a series of convex and concave
flexures, "giving them the appearance of so many colossal
entrenchments." With a broad artificial channel cut through its sunken
defiles and picturesque gorges, there would at once be opened a gateway
for the flow and reflow of the heavy commerce of the Western World.

In 1781 the practical and philosophic eye of Thomas Jefferson perceived
the national necessity for a great trans-Alleghany water-line, and early
in the year 1786, though still tossed on the wave of the Revolution, and
not yet recovered from the shock of British invasion, the State which
gave birth to the author of the "Declaration of Independence" declared
for the enterprise. With all the means and energy at its command it
pushed forward the work from year to year, and directed it, as Mr.
Jefferson had proposed, so as to connect the head-waters of the James
River, flowing from the Alleghany summits to t