les south of Washington lay Richmond, which
shortly became the capital of the Confederates, instead of Montgomery
in Alabama. As a brand-new capital it mattered little to the
Confederates, though at the very end of the war it became their last
remaining stronghold. The intervening country, which was in Southern
hands, was extraordinarily difficult. The reader may notice on the map
the rivers with broad estuaries which are its most marked features, and
with the names of which we shall become familiar. The rivers
themselves were obstacles to an invading Northern army; their
estuaries, on the other hand, soon afforded it safe communication by
sea.

In the Western theatre of war we must remember first the enormous
length of frontier in proportion to the population on either side.
This necessarily made the progress of Northern invasion slow, and its
proper direction hard to determine, for diversions could be created by
a counter-invasion elsewhere along the frontier or a stroke at the
invaders' communications. The principal feature of the whole region is
the great waterways, on which the same advantages which gave the sea to
the North gave it also an immense superiority in the river warfare of
flotillas of gunboats. When the North with its gunboats could get
control of the Mississippi the South would be deprived of a
considerable part of its territory and resources, and cut off from its
last means of trading with Europe (save for the relief afforded by
blockade-runners) by being cut off from Mexico and its ports. Further,
when the North could control the tributaries of the Mississippi,
especially the Cumberland and the Tennessee which flow into the great
river through the Ohio, it would cut deep into the internal
communications of the South. Against this menace the South could only
contend by erecting powerful fortresses on the rivers, and the capture
of some of them was the great object of the earlier Northern operations.

The railway system of the South must also be taken into account in
connection with their waterways. This, of course, cannot be seen on a
modern map. Perhaps the following may make the main points clear. The
Southern railway system touched the Mississippi and the world beyond it
at three points only: Memphis, Vicksburg, and New Orleans. A traveller
wishing to go, say, from Richmond by rail towards the West could have,
if distance were indifferent to him, a choice of three routes for part
of t