of this town by Bragg on the 8th of September; but I have
always fancied that that evacuation made Rosecrans over-confident,
and led him to think that he could force Bragg south as far as Rome.
After the Union army passed the river and Chattanooga fell into our
hands; we still kept pressing the enemy's communications, and the
configuration of the country necessitated more or less isolation of
the different corps. McCook's corps of three divisions had crossed
two difficult ridges--Sand and Lookout mountains--to Alpine in
Broomtown Valley with intentions against Summerville. Thomas's corps
had marched by the way of Stevens's Gap toward Lafayette, which he
expected to occupy. Crittenden had passed through Chattanooga, at
first directing his march an Ringgold. Thus the corps of the army
were not in conjunction, and between McCook and Thomas there
intervened a positive and aggressive obstacle in the shape of Bragg's
army concentrating and awaiting reinforcement at Lafayette. Under
these circumstances Bragg could have taken the different corps in
detail, and it is strange that he did not, even before receiving his
reinforcements, turn on McCook in Broomtown Valley and destroy him.

Intelligence that Bragg would give battle began to come to us from
various sources as early as the 10th of September, and on the 11th
McCook found that he could not communicate with Thomas by the direct
road through Broomtown Valley; but we did not begin closing in toward
Chattanooga till the 13th, and even then the Twentieth Corps had
before it the certainty of many delays that must necessarily result
from the circuitous and difficult mountain roads which we would be
obliged to follow. Had the different corps, beginning with McCook's,
been drawn in toward Chattanooga between the 8th and 12th of
September, the objective point of the campaign would have remained in
our hands without the battle of Chickamauga, but, as has been seen,
this was not done. McCook was almost constantly on the march day and
night between the 13th and the 19th, ascending and descending
mountains, his men worried and wearied, so that when they appeared on
the battle-field, their fatigued condition operated greatly against
their efficiency. This delay in concentration was also the original
cause of the continuous shifting toward our left to the support of
Thomas, by which manoeuvre Rosecrans endeavored to protect his
communications with Chattanooga, and out of which gr