Reenactors at the Battle of Hoovers Gap:The principal battle fought in the Tullahoma Campaign (also known as the Middle Tennessee Campaign) of the American Civil War.

On June 23, 1863, Rosecrans deployed forces to feign an attack on Shelbyville while massing forces against Bragg’s right. His troops struck out toward the gaps. On June 24, Maj. Gen. George H. Thomas’s men, spearheaded by Colonel John T. Wilder’s “Lightning Brigade”, attacked Hoover’s Gap. Wilder’s mounted infantry pushed ahead and reached the gap nearly 9 miles ahead of Thomas’s main body. Wilder’s men were armed with new Spencer repeating rifles and when they attacked the Confederate 1st (3rd) Kentucky Cavalry Regiment
http://en.wikipedia.org/wiki/Battle_of_Hoover%27s_Gap