Prelude to the Battle
Halleck Demands Action from Rosecrans
On October 24, 1862, President Abraham Lincoln relieved Major General Don Carlos Buell of his command of the Army of the Ohio and placed Major General William S. Rosecrans in charge of the newly formed Army of the Cumberland. Upon Rosecrans’ promotion, Union General-In-Chief Henry W. Halleck emphasized that “… the Government demands action, and if you cannot respond to that demand someone else will be tried.”
Battle of Stones River
Rosecrans established headquarters in Nashville, Tennessee, and quickly prepared his army for battle. On December 26, he moved his forces south to engage Confederate General Braxton Bragg and the Army of Tennessee, which was encamped at Murfreesboro. The two armies met at the Battle of Stones River (December 31, 1862-January 2, 1863). Rosecrans’ victorious army forced Bragg to withdraw to Tullahoma, Tennessee, thirty-six miles to the south, yielding Murfreesboro to the Union.
Bragg Protects Mountain Gaps Near Chattanooga
After the Battle of Stones River, Bragg deployed his army in a defensive line nearly seventy miles long along the Duck River from Shelbyville to Wartrace, Tennessee, northwest of Tullahoma. He intended to prevent Rosecrans from capturing the strategically important city of Chattanooga, Tennessee. Covering his flanks with cavalry, Bragg deployed small regiments to protect four gaps in the mountains separating the two armies. The four gaps were: Liberty Gap, Hoover’s Gap, Guy’s Gap, and Bellbuckle Gap.
In the meantime, Rosecrans established winter quarters at Murfreesboro, where his army remained relatively inactive for the next five and one-half months. During that time, Rosecrans resisted pressure from his superiors to press Bragg. Lincoln, Halleck, and Secretary of War Edwin Stanton feared that Rosecrans’ inactivity would enable Confederate leaders to detach soldiers from Bragg’s army to relieve Union General Ulysses S. Grant in his operations against Vicksburg. Finally, under threat of being relieved of his command, Rosecrans moved into action in late June 1863.
Rosecrans Attacks Rebel Defenses at Hoover’s Gap
On June 23, Rosecrans feigned attacks on each end of Bragg’s line. The next day he ordered Major General George H. Thomas’s 14th Corps and Major General Alexander McCook’s 20th Corps to strike the mountain gaps in the middle of Bragg’s line. Thomas assigned Colonel John Wilder’s mounted infantry brigade the task of leading the initial assault on Hoover’s Gap.
Setting out at dawn on June 24, 1863, during a steady rain that continued throughout the day, Wilder’s mounted infantry moved toward Hoover’s Gap ahead of Thomas’s main force. Wilder’s men were armed with newly introduced Spencer Repeating Rifles. Using the new rifles enabled the Union soldiers to fire seven rounds before needing to reload.
Federals Dislodge Rebel Defenders
When Wilder’s men neared Hoover’s Gap, they were nearly nine miles ahead of the bulk of Thomas’ corps. At about noon, they engaged Colonel J. Russell Butler’s 3rd Kentucky Regiment, the lone Confederate force defending the four-mile-long pass through the mountains. Advancing farther than expected, Wilder’s 1,500 soldiers quickly dislodged the surprised Rebels and took possession of the gap. Wilder then ordered his men to prepare for the counterattack he expected.
As Butler’s men retreated, they encountered Confederate Brigadier-General William B. Bate’s brigade. Upon learning of Butler’s withdrawal, Bate moved to regain possession of the gap. Three separate counterattacks during the afternoon proved unsuccessful. The Confederate breechloaders were no match for the firepower of the Spencers. By the time Rebel reinforcements arrived to support Bate’s attempt to regain the valley, Thomas’ 14th Corps arrived, and the fighting ended at about 7 p.m.
Aftermath of the Battle
When Thomas met with Wilder, he gushed “You have saved the lives of a thousand men by your gallant conduct today. I didn’t expect to get this Gap for three days.” Thomas christened Wilder’s command as the “Lightning Brigade.”
With the Federals in control of the gap, the Confederates probed the Union defenses for the next two days with little effect. On June 26, 1863, Bragg ordered his troops to withdraw toward his headquarters at Tullahoma. As Rosecrans’ army began pouring through the mountain gaps, Bragg retreated to Chattanooga, leaving the Union in possession of Middle Tennessee.
The federal victories at the Battle of Hoover’s Gap and the Tullahoma Campaign were unqualified successes for the Union forces in Tennessee. Unfortunately for Rosecrans, events happening at Vicksburg, Mississippi and Gettysburg, Pennsylvania at nearly the same time overshadowed his achievements. Although Bragg’s army escaped, Rosecrans drove the Confederacy out of Middle Tennessee with very few losses. The Union army suffered fewer than 600 casualties during the entire campaign. Confederate casualties during the battle and the campaign are unknown because Bragg wrote no battle reports, but the Union army captured 1,634 Rebels.