Bragg's force was considerably less than that which Buell had under his immediate command. Lee was at that time carrying on his tremendous campaigns in Virginia and Maryland so that no troops could be spared from that quarter to reinforce Bragg's undertaking. Price and Van Dorn had quite all they could do to hold their own against Grant at Corinth and Sherman at Memphis. It is true that Grant had been "stripped to the skin," as he expressed it, by calls upon him to reinforce Buell and to spare division after division for the army that was contending against Lee and doubtfully defending the Federal capital. But on the other hand Price and Van Dorn had been stripped equally bare to furnish Bragg with the troops with whom he was invading Kentucky.
And while Bragg was thus marching into his enemy's country with a force only about three fifths as numerous as that of his adversary and with no prospect of important reinforcement from any quarter, Buell was retreating upon a city strongly held, whose garrison would furnish an instant and a very strong reinforcement, while the mere threat of Bragg's advance was inducing the hurrying of multitudes of fresh troops from all the northwestern states, to the menaced cities of Cincinnati and Louisville. For it was clearly seen in Ohio, Indiana and Illinois, and even in Michigan, Wisconsin and Minnesota, that should Bragg succeed in establishing himself on the Ohio river the states north of that stream must become the ravaged and trampled theater of the next year's campaign, with a Confederate invading force swelled by enlistments from Kentucky and Tennessee to enormous proportions and reinforced by the fifty or sixty thousand Southern veterans whom the conquest of the Ohio by Bragg would instantly release from defensive work farther south. In brief, if Bragg could have captured and held Louisville by defeating Buell, it was morally certain that the Confederates would have been able, during the following spring, to invade the Northwest with an effective force of tremendous proportions. For Kentucky and Tennessee would in that case have become wholly Confederate, and the whole South would have joined in an effort to make decisive use of such an opportunity to end the war in triumph. Tens of thousands of seasoned troops employed during the summer of 1862 in garrisoning towns and protecting railroad lines would in that case have been set free to aid in an aggressive movement north of the Ohio. With the Confederates established at Louisville and holding the Ohio river as their line, there would have been no choice but for Grant to withdraw from Mississippi, West Tennessee and Kentucky, thus setting free not only the 30,000 or 50,000 men confronting his present position, but also the garrisons and armies about Vicksburg and along the several railroads in Mississippi and in northern Georgia and Alabama. It is certainly not an exaggeration to estimate that had Bragg succeeded, as he hoped, in seizing Louisville and meeting Van Dorn and Price "on the Ohio" as he said, the Confederates could and would have mustered at least 150,000 men for the invasion of the Northwest at the opening of the spring of 1863—an army greater than the South ever put into the field at any point during the entire continuance of the war.
And all this was a not impossible—indeed a not improbable—contingency. It is true that Bragg's force was in numbers inferior to Buell's in about the proportion of three to five. But it was massed at the outset and remained completely coöperating from beginning to end of the campaign. It had besides, the advantage of knowing what it intended and whither it was going, while Buell must vaguely guess its intentions and hold himself ready during a retreat, to meet his enemy wherever that enemy might see fit to strike.
In war these things offset superiority of numbers in a degree which it is difficult for the civilian reader to understand. He who can give battle or refuse it where he pleases, has a very great advantage over his adversary who must accept whatever is offered or else retreat at disadvantage.
Moreover Bragg had managed to get the start of Buell in their race for Louisville, and this advantage had been greatly increased by his success in breaking Buell's lines of march by burning bridges, tearing up railroads and capturing supply depots. For a time it seemed more than probable that Bragg would reach Louisville and occupy it before Buell could by any possibility get there. In that event Buell would have been cut off from all supplies, and only ordinary vigilance on the part of the Confederates would have been necessary to starve him into surrender—for if thus cut off, his stores could not have supported his army for more than three or four days at the utmost.
Still again, Bragg had another ground of hope. It often happens in war, that a smaller force, skilfully handled, masters a larger force. To go no further back than the Seven Days' battles around Richmond, and the campaign following, Lee had succeeded by the skilful handling of a comparatively small force in overcoming one army which greatly outnumbered his own, while paralyzing the purpose of other forces as great as his own, that had been sent to reinforce his enemy. With this and many other familiar illustrations of the possibility of achieving conspicuous military success against superior numbers present to his mind, it was not vainglorious on the part of Bragg, who believed in his own skill, to hope that if he could reach Louisville in advance of Buell, his army, inspirited by repeated successes on the march, and holding the vantage ground of possession, might successfully meet and defeat Buell's way-weary force, cut off, as in that case it would have been, from its objective, from all hope of assistance and even from very badly needed supplies.
Indeed, had Bragg achieved his purpose of pushing his columns into Louisville in advance of Buell's coming, it would have been almost a miracle for him to have failed in his resistance to the outmarched Federal commander's attempts to recapture the lost stronghold.
It was one of those fearful crises of the war,—like Sharpsburg and Gettysburg—in which the whole outcome of the struggle hung trembling in the balance, and the future alike of the Union and of the Confederacy was risked, as it were, upon the hazard of a die.
For while Bragg was thus dragging Buell back from northern Alabama and Georgia to the Ohio river and more than seriously threatening to make of that river the fortified frontier of the Confederacy, Lee was in Maryland, after having overthrown McClellan before Richmond and Pope at Manassas, and the National capital itself seemed in sore danger of capture. The year which had opened with the Union victories at Forts Henry and Donelson, presently followed by Grant's success at Shiloh, while McClellan's overwhelming divisions were near enough to Richmond to see the spires of that city's churches, seemed about to draw to a close so disastrous to the Federal cause as to leave it in worse case than at the beginning of the war or indeed at any time since the first defeat at Bull Run.
The National credit was impaired as it never had been before. The Confederates were moved to make of the eighteenth of September a day of Thanksgiving for a deliverance which they regarded as in effect accomplished.