February 12–16, 1862
The Battle of Fort Donelson was fought in northern Tennessee, near the Kentucky border, from February 12 through 16, 1862. Union forces of about 25,000 men under the command of Ulysses S. Grant forced the surrender of Fort Donelson and about 13,000 Confederate troops. The victory opened the Cumberland River as a pathway for Federal invasion of the South in the Western Theater of the American Civil War.
At the onset of the American Civil War, the State of Tennessee comprised the majority 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 relatively 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. Fort Donelson was built on a hill on the west bank of the Cumberland River near the Tennessee-Kentucky border. The fort had several shore batteries that could be used to fire on the river, and it was encircled on the landside by a system of earthworks.
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, located 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.
Following the surrender of Fort Henry, Grant turned his attention toward investing Fort Donelson. He marched his army toward the Cumberland River on February 12 and 13. After traversing the twelve-mile span between the two forts, Grantpositioned his troops in a semi-circle around the western side of Fort Donelson. On February 14, Foote's flotilla traveled up the Cumberland River and attempted to reduce the fort with naval gunfire from the eastern side. The bombardment proved to be ineffective, however, because the Confederates held the higher position. Eventually, Foote's gunboat's were forced to withdraw, setting the stage for a land engagement.
After the fall of Fort Henry, General A.S. Johnston, the Confederate commander in the West, had reinforced the garrison at Fort Donelson with 12,000 troops accompanied by generals Gideon J. Pillow, Simon B. Buckner, Sr., and John B. Floyd. Upon his arrival at Fort Donelson, Floyd assumed command of the 17,000-man garrison. Grant's army had swollen to about 25,000, with the arrival of reinforcements sent by Halleck. Seeing that they were surrounded, the Confederate generals decided to attempt a breakout, rather than being trapped by Grant's growing army.
On the morning of February 15, Confederate troops surged out of the fort, attacking the Union right flank, commanded by Brigadier General John McClernand. McClernand's men were driven back, but they were not routed. By early afternoon, reinforcements from the Union center arrived and stabilized the situation. Although a breakout was still possible, Pillow ordered his men back to their trenches to re-supply before the attempt. Taking advantage of the delay, Grant ordered a counterattack on the left, forcing the Rebels back into a defensive position. By nightfall, the Federals had reclaimed much of the ground that they had lost in the morning.
During the night, the Confederate commanders determined that their situation was now hopeless. Fearing harsh reprisals for political acts committed before the war, Floyd and Pillow chose to evade capture and fled during the night, turning command over to Buckner. The Federals awoke the next morning, surprised to see white flags of truce flying over Fort Donelson. Buckner requested an armistice and asked Grant for his terms of surrender. Grant replied that, "No terms except unconditional and immediate surrender can be accepted." Buckner had reason to believe that Grant would be more generous because of their personal relationship in the Union Army before the war. Nevertheless, he was forced to capitulate to what he termed Grant's "ungenerous and unchivalrous terms."
Ohio units that participated in the Battle of Fort Donelson included:
20th Regiment Ohio Volunteer Infantry
58th Regiment Ohio Volunteer Infantry
68th Regiment Ohio Volunteer Infantry
76th Regiment Ohio Volunteer Infantry
The Confederates suffered about 14,000 casualties at the Battle of Fort Donelson, compared with Union losses of about 2,500 men. However, the Rebel numbers were inflated by the 12,000 men captured. Although the total casualty rate for both sides was small in comparison with later battles in the war, the fall of Fort Donelson was a serious blow to the Confederacy. It forced them to give up activities in Kentucky and contract their operations deeper into Tennessee. The victory also boosted faltering morale in the North. In the aftermath of the battle, "Unconditional Surrender" Grant became an instant celebrity, and he was promoted to major general, second in command in the West. Coupled with the capture of Fort Henry, the Union now had control of two major waterways in the West from which to launch its impending invasion of the South.