The Battle of Hoover's Gap was the principal battle in the Tullahoma Campaign of the American Civil War, in which Union General William S. Rosecrans drove General Braxton Bragg’s Confederates out of Central Tennessee. Rosecrans’ feigned move on the western end of the Confederate line had left the eastern mountain passes lightly defended, and Colonel John T. Wilder's mounted infantry achieved total surprise when they attacked Hoover's Gap. Success was attributed both to Rosecrans’ brilliant deception tactics and the high morale of Wilder’s "Lightning Brigade", equipped with the new Spencer repeating rifle.

The Tullahoma campaign was a military operation conducted from June 24 to July 3, 1863, by the Union Army of the Cumberland under Maj. Gen. William Rosecrans, and is regarded as one of the most brilliant maneuvers of the American Civil War. Its effect was to drive the Confederates out of Middle Tennessee and to threaten the strategic city of Chattanooga.