Shiloh was an unexpected battle in an unforeseen place, to which Grant’s army was drawn down the Tennessee River by his victories at Forts Henry and Donelson. Its effect was to open up a new front in the centre of nineteenth-century America, in Tennessee, a crucial state for both Union and Confederacy, since it borders Alabama, Mississippi, and Georgia, and, across the Mississippi, Arkansas and Missouri. To the north it gives on to Illinois, Indiana, and Ohio, all solid and important Union territory, which was to be raided by Morgan’s cavalry in July 1862; eastward it also offered a route into South Carolina. Eastern Tennessee itself, covered by the tail of the Appalachians, was solidly pro-Union, the largest pocket of Unionist loyalty inside the Confederacy; being mountainous and relatively infertile, it was a region of subsistence farming almost without slaves.
At the beginning of the war, Tennessee was spared an outbreak of fighting because the state government, while not seceding, concluded an alliance with the Confederacy. This transparently evasive measure did not stick. Washington continued to regard Tennessee as a state of the Union and its elected representatives continued to sit in both houses of Congress. While the Confederacy also deemed Tennessee a member state, its political leaders formed at best a government in exile. The eastern counties had voted strongly against secession when a convention was held. Richmond was determined to fight to keep Tennessee out of the Union camp, but at first there were almost no opposing forces inside the state until Grant and Halleck appeared to organise the Army of the Tennessee, which was eventually confronted by Bragg’s Army of Tennessee. Thus a new front was opened, or a “line” as fronts were called in the Civil War. The term “front” did not come into use until the First World War, when it was borrowed from the vocabulary of meteorology, on the analogy with weather fronts of low and high pressure. There was an obvious front in Virginia in the region of high pressure between Washington and Richmond. Not so in the West, where troop density was low and there were few cities of importance. Yet gradually central Tennessee would become what a later generation would recognise as a distinctive front, whose crucial features were rivers and railroads. The key to organising the war in the region was to concentrate the scattered forces of the two sides and form campaigning armies. The main components were with Halleck at St. Louis and Beauregard’s Confederate survivors of Shiloh. Other Confederate troops were reaching Tennessee from the Atlantic coast and also from Arkansas. During April 1862, Halleck succeeded, by summoning Pope from the Mississippi front at New Madrid and Island No. 10 and Grant from near Shiloh, in forming an army of 100,000 men. Its generals included many of the Union’s future leaders, including not only Grant, but also Sherman and Sheridan, Don Carlos Buell, Rosecrans, and George Thomas, the “Rock of Chickamauga.” The Union army in the West was organised by Halleck; its three armies were named after the region’s major rivers, the Army of the Tennessee under Grant, the Army of the Ohio under Buell, and the Army of the Mississippi under Pope. Laymen may misunderstand the use of the term “Army.” It was entirely organisational and hierarchic. Battalions made regiments (two), regiments made brigades (three), brigades made divisions (three or more), divisions made corps (two or more), corps made armies (two or more). On the Union side armies were called after the river near which they operated (for example, the Potomac). In the Confederacy, armies were called after the region in which they operated (e.g., Northern Virginia). Armies also tended to be regional in composition, so that the Armies of the Tennessee and the Ohio, having been raised in the Midwest, were largely recruited from midwesterners.
Halleck opened his campaign against Beauregard by advancing on Corinth, a small railroad town in northern Mississippi which the Confederates had fortified. Intimidated by news of Halleck’s approach, Beauregard abandoned Corinth in late May and retreated southward. His army was much depleted by sickness and desertion. He nevertheless initiated a threat to middle Tennessee and Kentucky, and Halleck, rather than engage him, devoted his energies to fortifying Corinth further, thereby converting it into one of the strongest places anywhere in the zone of war. Halleck apparently expected the Southern troops to offer him an advantage by attacking his fortifications, but they did no such thing, instead attacking the Union railroads and threatening advances towards the lower Southern states. Halleck distributed his forces widely in an attempt to safeguard his new area of responsibility, choosing only an advance on Chattanooga as an active measure. In Washington, Lincoln was tiring of Halleck’s lethargy. He respected, however, his powers as an organiser and on July 11 summoned him to the capital to assume the post of general in chief, in McClellan’s place. As Lincoln would soon find, however, and Grant had already painfully learnt, Halleck was as temperamentally averse to offensive action as the young Napoleon. He was also equally dedicated to detail and to faultfinding with subordinates. Command in Tennessee passed to Grant, but the opportunity to strike during the interregnum was lost by the Confederates, since Beauregard, displeasing Jefferson Davis by taking sick leave at that inconvenient time, was also relieved of command, to be replaced by Braxton Bragg. Bragg, though a fighter, was also bad-tempered and alienated most of his subordinates by insulting them. Unlike both Halleck and McClellan, he had an offensive outlook and did not adhere to the Jominian idea that the purpose of a campaign was to manoeuvre an opponent out of position without actually fighting him. As soon as he succeeded Beauregard, Bragg set about confronting Grant in his headquarters at Corinth. His first plan was to march directly against him. He then reconsidered and decided on a roundabout approach through central Mississippi from the west. Grant, conscious of his threat, responded by getting up the forces, but Halleck, with his obsession about defending everywhere, had second thoughts about Tennessee and Kentucky.
While he was absent deploying his troops, Bragg left large detachments in northern Mississippi under Generals Price and Van Dorn, while he transferred to Kentucky, from which he appeared to threaten Louisville and Cincinnati. In early September 1862, he summoned Price and his 16,000 men. Grant, feeling understandable alarm, concluded correctly that the most likely place Price would strike was Iuka, a railroad village near Corinth which was a depot for a large supply of food and warlike stores. He selected a Wisconsin brigade, known after its mascot as the Eagle Brigade, to defend Iuka. Rosecrans led the advance while Grant, with General Edward Ord under command, waited in reserve. Rosecrans advanced to combat behind a cloud of skirmishers, with an accompanying battery. A tremendous firefight ensued. The ground was covered with dense thickets of scrub between which Blue and Gray dodged as the fight raged. By the end of the afternoon two Northern and two Southern brigades had suffered 790 and 525 casualties, respectively, out of strengths of 3,100 and 2,800. Despite the disparity, the Union got the better of the battle, forcing the Confederates to withdraw.
Grant was waiting in reserve only a few miles from the battlefield, but because of the direction of the wind and other factors was prevented by “acoustic shadow” from hearing any sound of the firing at all. He learnt that the battle had taken place from a despatch from Rosecrans only when it was over. He at once joined Rosecrans in a pursuit of Price and the defeated Confederates, but to Grant’s intense displeasure, Rosecrans abandoned the pursuit after Grant left him and Price made good his escape. He and Van Dorn then joined forces. Together they numbered about 22,000 men, whom Price led into southern Tennessee to threaten Corinth, Grant’s railroad base and centre of supply, the linchpin for his outposts at Jackson, Memphis, and Bolivar. By early October Grant detected that the rebel army, now commanded by Van Dorn, had repositioned itself to attack Corinth from the north. By October 3 the rebels were ready to attack. The Union troops, under the command of Rosecrans, were less well prepared, Rosecrans having been dilatory in concentrating his men. They were stationed in the old Confederate earthworks defending Corinth, behind which was a second and better position on College Hill. All day during October 3, the Confederates pressed hard against Rosecrans’s line, losing heavily but refusing to disengage. Instead they pressed onward, mounting one attack after another, pushing the Union troops back into the streets of Corinth. One formation that withdrew was the so-called Union Brigade, composed of regiments disorganised at Shiloh. Once among the houses of the town, however, they rallied and after meeting other units, resumed resistance and held the attackers at bay. General Rosecrans rode about what was left of his lines at this stage of the battle, shouting at his men to hold fast. Aided by Union artillery fire they did so, repelling one attack after another. Eventually the fighting concentrated round a Union earthwork, Battery Robinet, where the Union inflicted heavy casualties. Fifty-four Confederate dead were later found in the battery ditch, among them the colonel of the 2nd Texas, who had been hit thirteen times. At the culmination of the struggle for the battery, the Confederates turned in retreat. They had suffered 4,000 casualties, the Union 2,500. Moreover, the Confederates’ line of retreat was blocked by the Hatchie River, across which Van Dorn sought a crossing. Bridges were hard to find but Rosecrans did not press his pursuit. He was another example of a Union general who lacked the will and insight to exploit a victory when won. Rosecrans halted his army’s advance to the Hatchie for two successive nights, making its pace snaillike. His soldiers were frustrated and many pushed ahead without orders. When the flat bottom land of the Hatchie was reached, the Union troops found several Confederate batteries in place to defend the crossing places, and a murderous fight broke out, reinforced from both sides. Eventually it relapsed into stalemate, as Grant was able to recognise even from a distance. He sent orders to Rosecrans to back off, but as Van Dorn made good his escape, Rosecrans all too typically insisted that he was on the brink of a great victory and that Grant was cheating him of a golden opportunity. Van Dorn found sanctuary behind strong defences at Holly Springs in northern Mississippi, a position too strong to attack without lengthy preparation, as Grant also recognised. Rosecrans was to continue to complain of missed opportunity, but Grant knew better. He was already determined to close down the campaign in central Tennessee and to transfer his effort to a direct thrust on Vicksburg.
The campaign in central Tennessee had not, however, been without benefit to the Union. At its end, western Tennessee was largely swept clear of regular Confederate troops, though not of guerrillas, and northern Mississippi was in Union hands; loyal eastern Tennessee had not been liberated but was under threat of Union invasion. The great Union advantage in the region was that it lay adjacent to the Middle West, where troops could be raised in larger numbers.
The summer of 1862 was otherwise a time of troubles for the Union. The abandonment of the Peninsula Campaign and the humiliation of the withdrawal from Richmond was followed by the South’s assumption of the offensive in the East and its advances into northern Virginia again and then into Maryland. Defeat in the second battle of Bull Run was swiftly succeeded by the costly stalemate of Antietam. And it was not only in the eastern theatre that the war seemed to be going badly for the Union. In the West, Grant was failing to make progress in his campaign around Vicksburg to open up the valley of the Mississippi to Union traffic. There had been large-scale cavalry raids into the dubiously secure Union territories of Tennessee and the liberation of Arkansas underwent setbacks. Worst of all, in July, Braxton Bragg, the Confederate commander in Mississippi, embarked on a full-scale invasion of Kentucky. Kentucky was probably the most borderline of all the border states, counted by both sides as part of their governed territory and with regiments and large numbers of young men in both their orders of battle. The real danger for the Union in Kentucky, however, was not political but geographical. Its northern border was formed by the Ohio River, just across which lay the great city of Cincinnati, still more important than Chicago as an industrial and railroad centre, with a strong Union population acutely sensitive to the danger of military advances by the Confederacy. The way to Cincinnati, moreover, lay across easily marchable territory. If the Confederacy could drive a corridor across its central section, the territory of the Union would be bisected, in exactly the same way as the developing Union campaign in the valley of the Mississippi threatened to bisect the South. It was vital, therefore, that Bragg’s invasion should be defeated.
The difficulty was to organise a counter-offensive. The two Confederate cavalry leaders who had ridden so cavalierly through the region, Nathan Bedford Forrest and John H. Morgan, were still active, while a subsidiary army to Bragg’s, commanded by Edmund Kirby Smith, was advancing from Knoxville towards the Cumberland Gap, historic gateway into trans-Appalachia, from which he rapidly arrived at Richmond, Kentucky, only seventy-five miles south of Cincinnati. There he was confronted by a Union division, but all its troops were newly enlisted and it was swiftly dispersed at heavy loss of killed, wounded, and captured. Braxton Bragg had little enthusiasm for offensive war-making, but he was, at this stage and this place, a better bet than his opponent, Don Carlos Buell.
From Washington, however, Halleck so harassed Buell with directions to advance, to put pressure on Bragg, and to fight that eventually Buell had no alternative. He could not plead lack of strength, since he had by mid-September received the reinforcement of two divisions from Grant, while in Louisville and Cincinnati 60,000 recruits, raised locally, were being put through their training. During September, while Buell prudently retired towards Louisville, Bragg attempted to set the stage for a major battle to settle the balance of power in Kentucky. From his position near Louisville, he sent a request to Kirby Smith, who was then in the area of Lexington and Frankfort, the state capital, to meet him with his 20,000 men at Bardstown, south of Louisville. With their combined strength, Bragg believed he could defeat Buell and so settle matters in the borderlands. He also felt that fighting a major battle would pull the Kentuckians off the fence and bring them conclusively to the Confederacy.