he Potomac and desired "to defeat the last army of the
Federals in the east and drive the Northern Government from
Washington." The battle of _Gettysburg_ lasted three days (July 1-3,
1863). On the first, the army of Northern Virginia was uniformly
successful; on the second, the fortunes of battle swayed to and fro; on
the third, Lee decided to make a Napoleonic decisive attack with half
his available troops against Meade's centre. But the spirited attack
of the first 15,000, after penetrating the line, was checked, and the
remaining 15,000 did not arrive in support, so that the attack died
down, was repulsed, and withdrew in disorder.

At _Chattanooga_ (November 25, 1868) Grant's decisive attack was
successful, although delivered against a part of the position which
appeared to be impregnable, on account of the strength of the attack,
through {62} distribution in depth; 25,000 men were hurled against the
entrenchments in three lines, and the support of the third line carried
the waves of the attack through the defences.

DETAILING THE UNITS.--The commander will detail the units for carrying
out the Fire Attack, which will generally require one to three rifles
per yard of the objective. This force will be placed under a definite
commander, who will distribute it into a Forward Body to develop the
attack in the firing line; Supports, to enable the Forward Body to
assault the position; and Local Reserves to maintain or restore the
advantages gained, their main function being to repel counter-attacks
by similar bodies of the enemy and to maintain the offensive spirit.

The commander will also detail the units for carrying out the Decisive
Attack, which will require three to five rifles per yard of the portion
of the position against which it is projected. This force, under a
definite commander, is distributed for the attack in depth, so that the
strength and weight of the blow carries it home against all opposition.
The force is retained by the commander of the whole attacking troops,
to be thrown in at the right time and in the right place. It also
remains in hand to restore the battle in case of an unexpected check,
or to cover the withdrawal of the remainder of the troops if it is
desired to break off the engagement.

THE ARTILLERY.--The position of the artillery will be settled in
consultation with the artillery commander, the decision resting on the
objects in view, which are, to assist the infantry in its ad