Battle of Fort Donelson

The Battle of Fort Donelson was fought from February 11 to February 16, 1862, in the Western Theater of the American Civil War. The capture of the fort by Union forces opened the Cumberland River as an avenue for the invasion of the South. The success elevated Brig. Gen. Ulysses S. Grant from an obscure and largely unproven leader to the rank of major general, earning him the nickname "Unconditional Surrender" Grant in the process (using his first two initials, "U.S.").

The battle followed the capture of Fort Henry on February 6. Grant moved his army 12 miles overland to Fort Donelson on February 12 and February 13 and conducted several small probing attacks. (Although the name was not yet in use, the troops serving under Grant were the nucleus of the Union's Army of the Tennessee.) On February 14, U.S. Navy gunboats under Flag Officer Andrew H. Foote attempted to reduce the fort with naval gunfire, but were forced to withdraw after sustaining heavy damage from Donelson's water batteries.

On February 15, with their fort surrounded, the Confederates, commanded by Brig. Gen. John B. Floyd, launched a surprise attack against Grant's army, attempting to open an avenue of escape. Grant, who was away from the battlefield at the start of the attack, arrived to rally his men and counterattack. Despite achieving a partial success and opening the way for a retreat, Floyd lost his nerve and ordered his men back to the fort.

On the following morning, Floyd and his second-in-command, Brig. Gen. Gideon J. Pillow, panicked and relinquished command to Brig. Gen. Simon Bolivar Buckner (later Governor of the Commonwealth of Kentucky), who agreed to accept the unconditional surrender terms offered by Grant.