Fort Donelson National Battlefield preserves Fort Donelson and Fort Heiman, two sites of the American Civil War Forts Henry and Donelson Campaign, in which Union Army Brigadier General Ulysses S. Grant and Flag Officer Andrew Hull Foote captured three Confederate forts and opened two rivers, the Tennessee River and the Cumberland River, to control by the Union Navy. The commanders received national recognition for their victories in February 1862, as they were the first major Union successes of the war. The capture of Fort Donelson and its garrison by the Union led to the capture of Tennessee's capital and industrial center, Nashville, which remained in Union hands from February 25, 1862, until the end of the war, and gave the Union effective control over much of Tennessee. This struck a major blow to the Confederacy early in the war.

Fort Donelson was a fortress built early in 1862 by the Confederacy during the American Civil War to control the Cumberland River, which led to the heart of Tennessee, and thereby the Confederacy. The fort was named after Confederate general Daniel S. Donelson.