Who Won the Battle of Fort Donelson?

Initial Union attempts to storm the nearby Confederate capital city of Richmond, Virginia had been unsuccessful in 1861. Thus, the Union began the process of retaking Confederate territory in the Western Theater west of Virginia. The first target was Tennessee, the “top” of the South, which was easy to access from border states. Could the Union make inroads into well-defended Confederate territory and begin the process of winning the war?

The Union had just succeeded in taking Fort Henry, Tennessee on February 6, 1862 when it turned its focus to the larger Fort Donelson to the east. Fort Henry had guarded the Tennessee River, while Fort Donelson guarded the Cumberland River. Seizing both forts and controlling both rivers would let the Union move troops and supplies into the South more easily. Initial attempts to bombard Fort Donelson using Union gunboats failed on February 14, as the fort had heavy cannons to respond. Union general Ulysses S. Grant strategized what could be done and decided to mount an attack on land.

After a successful Confederate counterattack on February 15, Grant and his officers reasoned that the Confederates were understrength because they did not press their advantage. Using this reasoning, Grant ordered an assault in force. This attack successfully took all Confederate defensive territory up to the fort. That night, the commanders of Fort Donelson decided that they had to surrender, as they could not withstand a lengthy siege. On February 16, Confederate General Simon B. Buckner officially surrendered to Ulysses S. Grant.

Timeline of the Battle of Fort Donelson

By September 1861, this goal expanded to other rivers as well. The Confederates knew that the Cumberland and Tennessee Rivers were vulnerable to Union incursions and hurried to build forts on both rivers.

On January 22, 1862, the Union made its first gunboat contact with Fort Henry. Five days later, US President Abraham Lincoln ordered progress to be made with General War Order No. 1, prompting plans to advance along the rivers.

On January 30, plans were approved to attack Fort Henry, and Union ships left port on February 2. Simultaneously, General Ulysses S. Grant would advance on land.

Thanks to high waters due to snowmelt, the Union gunboats arrived at Fort Henry early and began bombardment on February 6, 1862. Knowing the fort could not withstand the gunboats, the Confederates abandoned Fort Henry, and soldiers traveled east to Fort Donelson.

On February 12, Grant began moving his soldiers toward Fort Donelson and had the installation surrounded by the 14th. Union gunboats were outgunned this time, forcing Grant to attack with his troops.

Despite a brief Confederate counterattack on February 15, Grant’s men closed firmly around the fort, and it surrendered the next day.

The Battle of Fort Donelson was caused by both a planned need to control the Cumberland River and the arrival of fleeing Confederate troops from Fort Henry. By striking Fort Donelson quickly, Grant deprived the Confederates of a chance to regroup and reinforce. Grant was also influenced by US President Abraham Lincoln’s desire for progress to be made on the war front; 1861 had passed with little real pressure on the Confederacy. Major battles, such as the Battle of Belmont, had been somewhat inconclusive.

Essentially, the Union needed a solid military victory. When the Confederate forces fled from Fort Henry and headed for nearby Fort Donelson, Grant knew he had to act swiftly. He was motivated not only by the prospect of a victory but also by the desirable territory: capturing Fort Donelson would give the Union significant control over western and central Tennessee. This would put Union territory next to eastern Tennessee, which was largely pro-Union and could likely be seized without much struggle as well.

Why Was the Battle of Fort Donelson Significant?

Capturing Fort Donelson was significant for multiple reasons. First, it gave the Union a solid military victory that showed progress on the war front. This was important after the defeat at the First Battle of Bull Run and the inconclusive result of the Battle of Belmont. Secondly, it began the long, slow process of retaking Confederate territory in the Western Theater. The Union Army had to show the public that this could be accomplished to maintain support for the war and quash calls for negotiations with the Confederacy.

Third, the seizure of Fort Donelson occurred with unconditional surrender, which was insisted upon by Union General Ulysses S. Grant. This set an important expectation for the war—the Union was serious. By not granting favorable terms, the Union was declaring its intent to recapture the South by force of arms. Failing to demand unconditional surrender might have emboldened the Confederacy, as they would have received most of their surrendering men back on parole. This would have extended the war by allowing the South to retain more of their soldiers over time.

1. Casualties

Casualties at the Battle of Fort Donelson were slight…aside from the 12,000 Confederate defenders captured. In terms of combat, the Union suffered greater casualties, with 500 men killed compared to slightly over 300 for the Confederates. Roughly 2,000 Union soldiers were wounded in action, compared to only 1,100 soldiers from the South.

2. Commanders

Union ground forces were led by Brigadier General Ulysses S. Grant, a middling West Point graduate and Mexican-American War veteran who had left the Army in 1854 before rejoining after the outbreak of the Civil War. Rear Admiral Andrew Hull Foote, a longtime veteran of the US Navy, commanded the gunboats on the Cumberland River. He served off the coasts of both Africa and China before the Civil War and passed away in 1863 from Bright’s disease after being promoted to full admiral.

Confederate forces were officially led by General John B. Floyd, though Floyd fled Fort Donelson before surrendering. Floyd turned over command to General Gideon Pillow, a seasoned veteran of the Mexican-American War, who in turn handed it over to Simon Bolivar Buckner. Buckner, a younger veteran of the previous Mexican war, surrendered the fort to Grant and was taken prisoner. Buckner was later paroled and went on to serve other commands for the Confederacy, while Floyd and Pillow saw their careers effectively ended by shirking command.

3. Number of Forces Involved

Roughly 24,500 Union troops under General Ulysses S. Grant and Rear Admiral Andrew Foote faced off against some 16,000 Confederate soldiers under General John B. Floyd. Outnumbered and cut off from resupply, the Confederates chose to surrender on February 16, 1862. Several thousand escaped with generals Floyd and Pillow, as well as with cavalry officer Nathan Bedford Forrest, meaning only 12,000 were captured instead of the full 16,000.

Fort Donelson National Battlefield is maintained by the National Park Service and includes a visitor center with historic exhibits. Tourists can take a self-guided driving tour of the vicinity, which includes the remains of the fort itself. They can also view the cannon placements overlooking the Cumberland River and the site of Confederate General Simon B. Buckner’s surrender. Visitors can spend the night in nearby Dover, Tennessee, which includes many historic sites.

5. Trivia: Introducing “Unconditional Surrender” Grant

The Battle of Fort Donelson was the first undisputed victory of Union General Ulysses S. Grant. His insistence on unconditional surrender, coupled with his first two initials, gave him the nickname “Unconditional Surrender” Grant. This fit with his tenacity, as Grant would later become famous for maintaining continuous pressure on Robert E. Lee’s vaunted Army of Northern Virginia. Previous Union generals had a bad habit of holding back after offensives, letting Lee’s army escape and regroup.

Aftermath of Fort Donelson: A Union Celebration

There were celebrations in the North upon news of the decisive Union victory at Fort Donelson. Grant was praised for his success and his insistence on unconditional surrender, which showed the South that there would be no “gentlemen’s agreements” when it came to the war. Losing the two forts led the Confederates to quickly abandon the city of Nashville, followed a week later by the city of Columbus. Tennessee became the first Confederate state to be completely controlled by the Union before the end of the Civil War in 1865.

Grant’s victory at Fort Donelson was followed a few months later by a larger victory in the Battle of Shiloh, which underlined the fact that the Confederacy could not defend its entire territory in the Western Theater. Although Grant’s victory at Shiloh was costly in terms of casualties, his “cleaner” victory at Forts Henry and Donelson helped keep him in President Abraham Lincoln’s good graces. Ultimately, it was Grant’s willingness to fight and press the enemy, both in regard to demanding unconditional surrender and accepting casualties, that eventually led to his promotion to general-in-chief of all Union armies.