In February 1862, General Ulysses S. Grant, a native Ohioan, led a Union force that captured Fort Donelson from the Confederacy.
Following his victory at Fort Henry on the Tennessee River, Grant marched his troops to Fort Donelson. Located in Tennessee, Fort Donelson guarded the Cumberland River. The Northerners arrived on February 12, 1862. The next day, a Union gunboat opened fire on the fort but did minimal damage to the structure. That evening additional ships and soldiers arrived, giving Grant almost a three to one advantage in the number of men available for a fight. The Union ships bombarded the Confederate position on February 14, but the ships again failed to achieve any major progress.
On February 15, Confederate soldiers attacked the Northern infantrymen. Although the Southerners had some initial success, Grant's men regrouped and occupied part of Fort Donelson's outer defenses along the Confederate right flank. That night, many of the Confederate soldiers fled from the fort, leaving a small number of men under Brigadier-General Simon Buckner's command. On the morning of February 16, Buckner sent a message to Grant, requesting surrender terms. Grant replied with, "No terms except an unconditional and immediate surrender can be accepted." Grant's response earned him the nickname "Unconditional Surrender Grant" and helped make him a hero in the North. Vastly outnumbered, the Confederates immediately surrendered and gave the Union control of much of the Cumberland River.
On the afternoon of February 16, Grant and Buckner met to formalize the surrender. These two men had attended the United States Military Academy at West Point together and they were good friends. Grant even paid Buckner some money to settle an old debt that he owed the Southerner at this meeting. Despite the Northerner's victory, Buckner and Grant stayed friends for the rest of their lives. Buckner served as a pallbearer at Grant's funeral.
The Northern victories at Fort Henry and Fort Donelson were the first significant ones for the Union in the western theater of the war. They also gave the Northern military unfettered access to the Tennessee and Cumberland Rivers, allowing the Union to gain deeper access into the South and an easier means to transport troops and supplies. These victories enhanced Northern morale, including that of Ohioans. Previously, many Northerners were demoralized by Southern victories at the Battles of First Bull Run and Ball's Bluff in 1861. The Battles of Fort Henry and Fort Donelson also signaled Grant's ascendancy as a prominent military leader for the North.