At the onset of the American Civil War, the State of Tennessee comprised most of the northern border of the Confederate States of America in the West. Defending that border was difficult for the Confederacy because three major rivers (the Mississippi, which flows south to the Gulf of Mexico, and the Tennessee and Cumberland rivers, which flow north to the Ohio River) provided comparatively easy access to the South. In 1861, the State of Tennessee constructed earthen forts on the Tennessee and Cumberland rivers to prevent federal invasions from the north.
Grant Captures Fort Henry
By late 1861, President Abraham Lincoln was pressuring Union commanders in the West to invade the South. On January 30, 1862, the Western Theater commander, General Henry Halleck, reluctantly approved Brigadier General Ulysses S. Grant’s request to attack Fort Henry, on the Tennessee River, just twelve miles west of Fort Donelson. Eager to move, Grant left Cairo, Illinois on February 2, with 15,000 soldiers, plus a flotilla of seven gunboats commanded by United States Navy Flag Officer Andrew Hull Foote. On February 6, Confederate Brigadier General Lloyd Tilghman surrendered Fort Henry after a seventy-five-minute bombardment by Foote’s gunboats.
Grant Captures Fort Donelson
Following the surrender of Fort Henry, Grant turned his attention toward investing Fort Donelson, located just twelve miles to the east of Fort Henry on the Cumberland River. After a failed breakout on February 15, the Confederate commander of Fort Donelson, General Simon B. Buckner, surrendered Fort Donelson to Grant the next day.
Johnston Abandons Kentucky and Nashville, Tennessee
The fall of Fort Henry and Fort Donelson were serious blows to the Confederacy. It forced General A. S. Johnston, the commander of Rebel forces in the West, to abandon Kentucky and to fortify his position deeper in Tennessee. The fall of the two forts also provided the Federals with two major waterways in the West from which to launch an invasion of the South. As Union armies surged into Tennessee, Johnston abandoned Nashville and moved even farther south in late February, rather than risk suffering a major battlefield defeat.
Halleck Plans to Merge Union Armies
Halleck ordered Grant to march his army south to the community of Pittsburg Landing, Tennessee, near the Tennessee-Mississippi border, and to await General Don Carlos Buell’s Army of the Ohio, which had just captured Nashville, Tennessee. Halleck’s intention was to merge the two armies and to move south to cut the Memphis & Charleston Railroad line at Corinth, Mississippi.
Grant Awaits Buell’s Arrival
By early April, Grant encamped his army of nearly 50,000 men along the western side of the Tennessee River near Pittsburg Landing. Not believing that Johnston’s army was within striking distance, Grant used the time to drill his troops while waiting on Buell’s army instead of constructing defensive fortifications. Johnston, however, stopped retreating. Rather than waiting to confront the combined Union armies at Corinth, he chose to surprise Grant’s unprepared men at Pittsburg Landing.
April 6 – Johnston Attacks and Federals Flee
Despite reports of Rebel troop movements in the area in the days before the battle, Johnston’s Army of the Mississippi (aka Army of Mississippi) surprised the Federals by launching an attack on the morning of April 6. In the ensuing confusion, many of the Yankees fled in panic. Others formed makeshift lines of battle and mounted some resistance. Gradually, however, the Confederates drove the Federals back to a defensive position behind Shiloh Church.
Federals Rally at the “Hornet’s Nest”
As the Confederates pressed their advance, Union soldiers commanded by Brigadier General Benjamin Prentice and Brigadier General W. H. L. Wallace 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 mortally wounded Wallace and killed or captured many of his men, the seven-hour Union stand bought valuable time for Grant to reorganize his men and to establish a final defensive line. During the attempt to dislodge the Yankee defenders from the Hornet’s Nest, the Confederacy suffered a severe setback when General Johnston suffered a mortal wound.
Federals Repulse Final Assault
As the first day of the battle concluded, the Confederate advance stalled. Grant had reestablished order amongst his troops and set up a defensive line near the river. Johnston’s replacement, General P. G. T. Beauregard, attempted a final assault during the early evening, which the Federals repulsed. At nightfall, Beauregard suspended the attack.
Beauregard Claims Victory
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 when reinforcements from Buell’s army arrived. Although the size of the armies was about equal on the first day of the battle, the Federals outnumbered Beauregard’s army when the sun rose.
April 7 – Federals Strike Back and Rebels Retreat
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. Despite several attempts to stop the Union advance, the Confederates gradually lost the ground they had captured the previous day. Eventually, Beauregard acknowledged defeat and ordered a retreat back to Corinth. To Buell’s dismay, Grant did not pursue the escaping Rebels. Except for a short cavalry encounter at a place called Fallen Timbers on April 8, the Battle of Shiloh had ended.
Although Union forces won the battle, inflammatory articles in the Northern press severely criticized Grant for being surprised by Johnston’s attack. Rumors circulated that Grant was drunk as Rebels bayoneted Union soldiers in their tents as they slept. Later historians credited Grant with rallying his men, maintaining his calm under dire circumstances and turning chaos into victory.
After the battle, Halleck merged his armies and assumed personal command, relegating Grant to his second-in-command. When Union officials later called Halleck to Washington and promoted him to the chief of all Union armies, Grant returned to field command and resumed his string of victories over Southern forces.
The Battle of Shiloh cost each side about 13,000 casualties, but the conflict that began so favorably for the Confederacy ended as a decisive Union victory. The Rebels could not prevent Halleck from merging the armies of Grant and Buell. Nor did they drive the Yankees back north. Johnston’s death considerably diminished Confederate leadership in the West. Finally, the Union victory at Shiloh paved the way to the fall of Corinth in May, and the federal occupation of Chattanooga, Tennessee, and Vicksburg, Mississippi in 1863.