Officially organized on March 5, 1862, the Army of the Mississippi transitioned into the Army of Tennessee, the Confederacy's preeminent fighting force in the Western Theater of the American Civil War.
Although not officially organized until March 5, 1862, the roots of the Army of the Mississippi trace back to 1861. Prior to Tennessee’s secession from the Union on June 8, 1861, the state legislature authorized Governor Isham Harris to enter a military league with the Confederate States of America. Soon after this authorization, a large majority of Tennesseans ratified an ordinance of secession, the legislature enacted a measure to raise an army of 55,000 men. Harris initially appointed Gideon Pillow to command the state’s forces and sent him to Memphis to begin preparations for seizing control of the Mississippi River.
On July 13, 1861, Governor Harris authorized the Tennessee Provisional Army to serve under Confederate General Leonidas Polk, although the state’s forces would not join the Provisional Confederate Army until July 31. Five weeks later, Polk committed one of the bigger blunders of the Civil War. On September 4, 1861, without authorization, Polk violated Kentucky’s neutrality by ordering Pillow to invade the Bluegrass State to occupy Columbus, an important port on the Mississippi River. Within one week, voters in Kentucky elected a new Unionist legislature that acted to end the state’s neutrality. The South lost any hopes of persuading the Kentucky commonwealth to join the Confederacy for the rest of the war.
Albert Sidney Johnston Takes Command
Six days after Polk’s impolitic invasion of Kentucky, President Jefferson Davis reorganized the Confederate defenses in the West. On September 10, 1861, the Confederate War Department issued Special Orders, No. 149, appointing General Albert Sidney Johnston to the command of the Western Military Department, which encompassed most of the Confederacy west of the Appalachian Mountains and east of the Mississippi River.
Upon assuming his command, Johnston went to work organizing the Confederate forces in the West. With Polk having opened the door for Union invasions into the South through Kentucky, Johnston’s most pressing challenge was trying to defend a three-hundred-mile front stretching from the Cumberland Gap in the Appalachian Mountains to the Mississippi River. With only 40,000 raw and under-armed Confederate troops at his disposal, the task was hardly possible without first giving ground.
Setbacks in Kentucky and Tennessee
Johnston consolidated his forces at Bowling Green, Kentucky, the heart of his defensive line. During the winter, however, his position became untenable. On January 19, 1862, Union soldiers, commanded by Brigadier-General George H. Thomas, defeated Major General George B. Crittenden’s Rebel forces at the Battle of Mill Springs, forcing the Confederates to abandon eastern Kentucky and to retreat into Tennessee. By February 15, Federal forces commanded by Ulysses S. Grant had taken possession of Fort Henry, on the Tennessee River, and Fort Donelson, on the Kentucky River.
The fall of the forts provided the Federals with two major waterways in the West from which to launch invasions into the South. As Union soldiers surged into Tennessee, Johnston ordered his troops at Bowling Green to fall back to Murfreesboro, near Nashville, on February 13, 1862. Two weeks later Johnston evacuated central Tennessee and retreated farther south to Corinth, Mississippi. Johnston’s withdrawal from Tennessee enabled Brigadier-General Don Carlos Buell and the Army of the Ohio to occupy Nashville on February 25, making it the first Confederate state capital to fall during the Civil War.
Just prior to the fall of forts Henry and Donelson, the Confederacy transferred General P. G. T. Beauregard to the Western Theater. Beauregard arrived in Bowling Green in poor health and reported to Johnston on February 4, 1862. Johnston charged Beauregard with the defense of the Mississippi Valley and placed him in command of Leonidas Polk’s garrison at Columbus, Kentucky. After the forts fell, Beauregard recognized that the position was untenable. He ordered Polk to abandon the “Gibraltar of the West” and to move his troops farther south. On March 3, 1862, Union troops occupied Columbus. Soon thereafter, Brigadier-General John Pope’s successful operations against New Madrid, Missouri and Island No. 10 on the Mississippi River left the Union solidly in control of Kentucky and western Tennessee.
By early March, Beauregard’s health had improved, enabling him to take direct control of the troops assigned to him. On March 5, 1862, Beauregard issued a message announcing that he was assuming command of the force that he designated as “the Army of the Mississippi.”
Organizing the Army at Corinth, Mississippi
When Johnston arrived in Corinth on March 22, 1862, he was done retreating. With the help of Beauregard, he began reorganizing the forces at hand for an offensive in Tennessee. Besides the troops from Johnston’s department, Major General Braxton Bragg had arrived earlier in the month from Pensacola with 10,000 well-trained soldiers, and Brigadier-General Daniel Ruggles brought 5,000 reinforcements from New Orleans. Johnston now had over 40,000 men under his command. On March 29, Johnston issued General Orders, No. 1-8 (Headquarters of Forces at Corinth, Mississippi), announcing the consolidation of the troops in the Western Military Department as the Army of the Mississippi.
After organizing the army, Johnston and Beauregard set about developing a plan to regain Tennessee by striking Major General Ulysses S. Grant’s Army of the Tennessee and then turning on Major General Don Carlos Buell’s Army of the Ohio before the two forces could unite.
Battle of Shiloh (April 6–7, 1862)
By early April, Grant had nearly 50,000 men encamped along the western side of the Tennessee River near Pittsburg Landing. Not believing that Johnston’s army was within striking distance, Grant drilled his troops, rather than to build defensive works, while he awaited Buell’s arrival.
Despite reports of Rebel troop movements in the area in the days before the battle, the Army of the Mississippi launched an attack on the morning of April 6, 1862, that surprised the Federals. In the ensuing confusion, many of the Yankees fled in panic. Others re-formed their lines of battle and mounted some resistance, but the Confederates gradually drove them back.
As the Rebels pressed their advance, Union soldiers made a stand at a position since popularized as the “Hornet’s Nest,” near a road now known as the “Sunken Road.” Although the Rebels eventually killed or captured many of the desperate Federals, the seven-hour stand bought valuable time for Grant to reorganize his men and to establish a defensive line. In their attempt to dislodge the defenders of the Hornet’s Nest, the Rebels suffered a serious loss, when the Yankees mortally wounded General Johnston. After Johnston fell, Beauregard assumed command of the Confederate forces.
As the first day of the battle concluded, the Confederate advance had spent itself. Grant had reestablished order amongst his troops and set up a defensive line near the river. After the Federals withstood a final assault that evening, Beauregard called off the attack.
That night, Beauregard sent a telegram to Confederate President Jefferson Davis, proclaiming “A complete victory.” Beauregard went to bed expecting to drive Grant’s army across the Tennessee River the next day. Grant, however, had established a strong position, and reinforcements from Buell’s army were arriving on the scene. Although the size of the armies was about equal on the first day of the battle, the Federals now outnumbered Beauregard’s forces.
On the morning of April 7, to Beauregard’s surprise, Grant and Buell launched a counterattack. Outnumbered and running low on ammunition, the Rebels began to fall back, losing ground that they had captured the previous day. Eventually, Beauregard knew that he had lost and began an orderly retreat to Corinth, ending the Battle of Shiloh.
After reaching Corinth, Beauregard maintained command of the Western Department but placed Braxton Bragg in charge of the Army of the Mississippi on May 6, 1862 (General Orders, No. 37, Headquarters of the Forces). Meanwhile, the combined Union forces of Grant and Buell, now commanded by Major General Henry Halleck, advanced upon Corinth, Mississippi, and settled into a siege of the city in late May. Inside the city, typhoid and dysentery caused by bad water wracked Beauregard’s soldiers. Facing the prospect of being enveloped by the massive Federal force of nearly 125,000 soldiers, Beauregard saved the Army of the Mississippi with a brilliantly executed evacuation on May 29, 1862. Despite the circumstances that compelled the withdrawal, Jefferson Davis was critical of Beauregard’s decision.
Beauregard reached Tupelo, Mississippi, and established new headquarters on June 7, 1862. The Army of the Mississippi arrived on June 9. Five days later, Beauregard received a certificate of disability for a recurring throat problem. On June 15, Beauregard informed General Samuel Cooper, adjutant and inspector general at the War Department, that he was transferring “the command of the forces and of this department to the next officer in rank, General Braxton Bragg.” Beauregard then traveled to Alabama to recuperate, while Bragg reorganized the army. When President Davis learned that Beauregard had left his post on an unauthorized sick leave, he relieved Beauregard of his command of the Western Department. On June 20, 1862, Davis informed Bragg that he was the new department commander. Soon after his appointment, Bragg issued General Orders, No. 22, temporarily handing off command of the Army of the Mississippi to Major General William J. Hardee on July 5, 1862.
Confederate Heartland Campaign
As commander of the Western Department, Bragg devised a plan known as the Confederate Heartland Campaign to shift the focus of the war in the Western Theater by invading Kentucky. Bragg believed that most residents in that border state supported the Confederacy and that many of them would join the Southern army if given the opportunity.
On August 15, 1862, Bragg issued General Orders, No. 116 (Department No. 2), resuming his command of the Army of the Mississippi. Two weeks later, on August 28, he left Chattanooga, Tennessee with 34,000 soldiers to launch his invasion of Kentucky. Once in the Bluegrass State, Bragg planned to combine forces with Lieutenant General Edmund Kirby Smith’s 18,000 soldiers, stationed near Knoxville, Tennessee, and to move against Buell’s Army of the Ohio.
On September 17, the Army of the Mississippi captured an important rail station at Munfordville, Kentucky, along with 4,000 Union soldiers, at the Battle of Munfordville (September 14–17, 1862). On October 4, events were so promising that Bragg took part in the inauguration of Richard Hawes as the provisional Confederate governor of Kentucky. On October 8, Bragg won a tactical victory over Buell at the Battle of Perryville. Nonetheless, running short of supplies and ammunition and faced with the prospect of squaring off with Buell’s reinforced army on the following day, Bragg withdrew during the night.
After the Battle of Perryville, Bragg retreated to Harrodsburg, Kentucky, where he finally joined forces with Kirby Smith. The combined Confederate army was now comparable in size to Buell’s army. Nevertheless, Bragg lost his enthusiasm for the campaign. The Kentucky recruits that he expected never materialized, and he believed that his supply lines were too vulnerable and insufficient for his army to remain in the state. Over the objections of Smith, Polk, and other subordinates, Bragg called off the campaign and evacuated Kentucky, leaving the state in Union control for the rest of the war.
The Army of the Mississippi Becomes the Army of Tennessee
Following the failed Heartland Campaign, President Davis summoned Bragg to Richmond to answer to the charges of his subordinate officers. During Bragg’s absence, Lieutenant General Leonidas Polk commanded the Army of the Mississippi from September 28, through November 7, 1862. Satisfied with Bragg’s rebuttal, Davis ignored requests to relieve the general of his command. Understandably, Bragg’s relationships with his subordinate officers were strained when he rejoined his forces. On November 7, 1862, Bragg issued General Orders, No. 143, reorganizing the Army of the Mississippi into two corps commanded by Polk and William J. Hardee. Two weeks later, he issued General Orders, No. 151, on November 20, again shaking up the command structure. Bragg created a third army corps, commanded by Edmund Kirby Smith, from troops from the Department of East Tennessee. The general designated his newly structured command as the Army of Tennessee, thus bringing an end to the Army of the Mississippi.