eneral Pope's defeat, to take command of every thing, and see to the
safety of Washington; and, finding himself at length at the head of an
army of about one hundred thousand men, he proceeded, after the manner
of a good soldier, to protect the Federal capital by advancing into
upper Maryland in pursuit of Lee.

III.

MOVEMENTS OF THE TWO ARMIES.

General Lee was already moving to the accomplishment of his designs,
the capture of Harper's Ferry, and an advance into the Cumberland
Valley.

His plan to attain the first-mentioned object was simple, and promised
to be successful. Jackson was to march around by way of "Williamsport
and Martinsburg," and thus approach from the south. A force was
meanwhile to seize upon and occupy the Maryland Heights, a lofty
spot of the mountain across the Potomac, north of the Ferry. In like
manner, another body of troops was to cross the Potomac, east of the
Blue Ridge, and occupy the Loudon Heights, looking down upon Harper's
Ferry from the east. By this arrangement the retreat of the enemy
would be completely cut off in every direction. Harper's Ferry must
be captured, and, having effected that result, the whole Confederate
force, detached for the purpose, was to follow the main body of this
army in the direction of Hagerstown, to take part in the proposed
invasion of Pennsylvania.

This excellent plan failed, as will be seen, from no fault of the
great soldier who devised it, but in consequence of unforeseen
obstacles, and especially of one of those singular incidents which
occasionally reverse the best-laid schemes and abruptly turn aside the
currents of history.

Jackson and the commanders cooeperating with him moved on September
10th. General Lee then with his main body crossed the South Mountain,
taking the direction of Hagerstown. Meanwhile, General McClellan had
advanced cautiously and slowly, withheld by incessant dispatches from
Washington, warning him not to move in such a manner as to expose that
city to danger. Such danger existed only in the imaginations of the
authorities, as the army in advancing extended its front from the
Potomac to the Baltimore and Ohio Railroad. General McClellan,
nevertheless, moved with very great precaution, feeling his way, step
by step, like a man in the dark, when on reaching Frederick City,
which the Confederates had just evacuated, good fortune suddenly came
to his assistance. This good fortune was the discovery of a copy of
G