The Lightning Brigade, also known as Wilder's Brigade or the Hatchet Brigade, was a mounted infantry brigade from the American Civil War in the Union Army of the Cumberland from March 8, 1863, through November 1863. A novel unit for the U.S. Army, its regiments were nominally the 1st Brigade of Maj. Gen. Joseph J. Reynolds' 4th Division of Thomas' XIV Corps. Operationally, they were detached from the division and served as a mobile mounted infantry to support any of the army's corps. Colonel John T. Wilder was its commander. As initially organized, the brigade had the following regiments: 92nd Illinois Mounted Infantry: Col. Smith D. Atkins (after 10 July 1863) 98th Illinois Mounted Infantry: Col. John J. Funkhouser (w), Lt. Col. Edward Kitchell 123rd Illinois Mounted Infantry: Col. James Monroe 17th Indiana Mounted Infantry: Maj. William T. Jones 72nd Indiana Mounted Infantry: Col. Abram O. Miller 18th Independent Battery Indiana Light Artillery: Capt. Eli Lilly
Formation Throughout 1862, Major General William S. Rosecrans and his Army of the Cumberland were driven to distraction by Confederate cavalry and irregulars. Like many in the U.S. Army, they were coming to the realization of how hasty and in error the McClellan clique had been in resisting the raising of volunteer cavalry as seen by their own experience as well as McClellan's failure in the Peninsula Campaign. The federal government had already put out a call to the states in the summer of 1862 for cavalry regiments, but they were just recently being raised and were not yet active in sufficient numbers.
Initial issue
In response to John Hunt Morgan's October 1862 raid, Rosecrans sent the brigade in pursuit. In an effort to move faster, the brigade mounted mule wagons. The brigade nearly caught Morgan, but when they entered the last Confederate bivouac, Morgan had escaped. In this effort, John T. Wilder served as the commander of the 17th Indiana, one of the component regiments in the brigade.
On 22 December 1862 in Gallatin, Tennessee, John T. Wilder took over command of the brigade which at that time consisted of the 98th and 123rd Illinois Infantry Regiments, the 17th, 72nd, and 75th Indiana Infantry Regiments, and the 18th Indiana Battery of Light Artillery. His initial combat mission was to pursue another of Morgan's raids into Kentucky intended to sever the Army of the Cumberland's primary supply line. Lacking sufficient cavalry to screen his army as he moved south toward what would be the Battle of Stones River as part of the Stones River Campaign, Rosecrans again had to use infantry to chase off Morgan. Trying to speed their movement, these infantry units deployed partially by rail. Wilder also unsuccessfully tried to replicate the use of mule-drawn wagons with the addition of men mounting the mules pulling the wagons. Unfortunately, they still traveled the majority of the pursuit on foot over unpaved roads. Despite the use of rail and wagons to speed up the pursuit, the mission was a failure with Morgan's command escaping at the Rolling Fork River. The difference in speed between cavalry and infantry made the pursuit near impossible.
As a result of the failure, Rosecrans and his subordinates revisited the experiment with wagons from the October events and realized the solution to their problems was the early role of dragoons as mounted infantrymen. Several times, Rosecrans wrote to the Union General-in-Chief Major General Henry Wager Halleck stating his desire to convert or establish units of mounted infantry and asking for authorization to purchase or issue enough tack to outfit 5,000 mounted infantry. He believed that he needed to outfit all of his cavalry with repeating weapons. When he felt he was not being heard, he went over Halleck directly to War Secretary Edward M Stanton. In a dispatch from 2 February, he explained his reasons to Secretary Stanton:
This stepping out of the chain of command seemed to work as it drew a quick response from Halleck promising the "best arms" and "superior arms" as soon as they became available from the factories. Of note, Halleck reminded Rosecrans that "you are not the only general who is urgently calling for more cavalry and more cavalry arms" and that "Grant, Sibley, Banks, Hunter, Foster, Dix, and Schenck" all wanted "more cavalry."
Conversion to mounted infantry
In Wilder, an innovative and creative man, Rosecrans found an eager acolyte for mounted infantry as a solution. On 16 February 1863, Rosecrans authorized Wilder to mount his brigade. The regiments also voted on whether to convert to mounted infantry. All but the 75th Indiana voted to change to mounted infantry. The 123rd Illinois who had wanted to become mounted infantry transferred from the 1st Brigade of the 5th Division of XIV Corps to replace them. Through February 1863, Wilder obtained around a thousand mules to mount his command, not from the government but scavenged from the countryside. Due to the obstinacy of the mules, horses were frequently seized from local stocks in Tennessee as contraband and replaced the mules. Wilder boasted that it did “not cost the Government one dollar to mount my men.”
In theory and in practice, the brigade would use their mounts to travel rapidly to contact, but upon engagement, the soldiers would fight dismounted. Due to this speed of deployment, the unit earned the nickname, "The Lightning Brigade", and it would prove the validity of its conversion in the campaign in the Western theater. They were also sometimes known as the "Hatchet Brigade" because they received long-handled hatchets to carry instead of cavalry sabers.
As well as mounting the command for faster deployment, Wilder felt that muzzle-loaded rifles were too difficult to use traveling on horseback. Like Rosecrans, he also believed that the superiority of repeating rifles were worth their price in return for the great increase in firepower. The repeating rifles also had the standoff range similar to the standard infantry Lorenzes, Springfields, and Enfields in use by the Army of the Cumberland. He felt the repeating and breech loading carbines in use by the Federal cavalry lacked the accuracy at long range that his brigade would need.
While Rosecrans looked at the regiment's five-shot Colt revolving rifle that would equip other units in the Army of the Cumberland (particularly seeing action with the 21st Ohio Volunteer Infantry Union forces at Snodgrass Hill during the Battle of Chickamauga), Wilder was initially opting for the Henry repeating rifle as the proper weapon to arm his brigade. In early March, Wilder arranged a proposal for New Haven Arms Company (which later became famous as Winchester Repeating Arms) to supply his brigade with the sixteen-shot Henry if the soldiers paid for the weapons out of pocket. He had received backing from banks in Indiana on loans to be signed by each soldier and cosigned by Wilder. New Haven could not come to an agreement with Wilder despite the financing.
After attending a promotional demonstration by Christopher Spencer for the Army of the Cumberland of his Spencer repeating rifle, Wilder proposed the Henry arrangement to Spencer. Spencer agreed and got the Ordnance Department to send a shipment to the Army of the Cumberland. The majority of the shipment armed all men of the brigade.
The brigade's new weapon used a seven rimfire-cartridge tubular magazine that came through the butt. This rifle's increase in firepower would quickly make it one of the most effective weapons in the Civil War. With new mounts and new weapons, the brigade worked out new tactics. Alongside the Army of the Cumberland's other mounted infantry units, Wilder developed new training and tactics through May and June 1863. By the middle of the latter month, the brigade's soldiers had realized the advantages the breech-loading repeating rifle held over the muzzleloader, and they exuded confidence in themselves, their leaders, their new tactics, and their treasured new weapons.
Conflicting visions
In his 2002 thesis, Harbison illustrates the disconnect between Rosecrans' and Wilder's expectations. Rosecrans appears to have envisioned a mounted rifle organization similar to those in the U.S. Army. These units were armed with rifles and fought on foot (with the rifle giving them a greater range of lethality) yet still performed the traditional cavalry roles of scouting enemy weaknesses and location, security of the flanks or rear the parent command, countering enemy cavalry, countering enemy infantry attacks, being a mobile reserve, inflicting the coup de grace to a faltering enemy, covering one's own retreat, and pursuit of a retreating foe. As such, when the carbines of the regular cavalry became rifled, these units were converted to Dragoons and eventually cavalry. Wilder saw the organization as an infantry formation with the basic roles of attack and defense. In fact, to preclude them being mistaken for cavalry, Wilder had the brigade remove the yellow cloth tapes from the outseam of the standard riding trousers which had been issued from the quartermasters. Wilder stressed to his regiments that the mounts were a means of moving faster and that they were infantry. As such none of the training involved scouting and screening.
Tullahoma Campaign
Hoover's Gap
On June 23, 1863, Rosecrans deployed forces to feign an attack on Shelbyville while massing forces against Braxton Bragg's right. His troops moved out toward Liberty, Bellbuckle, and Hoover's Gaps through the Highland Rim (near Beechgrove, Tennessee). On June 24 in pouring rain that would persist for 17 days (Union soldiers spread the humorous rumor during the campaign that the name Tullahoma was a combination of the Greek words "tulla", meaning "mud", and "homa", meaning "more mud".) Maj. Gen. George H. Thomas's men, spearheaded by Colonel John T. Wilder's "Lightning Brigade", made for Hoover's Gap. The brigade showed the advantage of their speed despite the weather by reaching the gap nearly 9 miles ahead of Thomas's main body.Despite orders from the divisional commander, General Joseph J. Reynolds to fall back to his infantry, which was still six miles away, Wilder decided to take and hold the position.
The command surprised Confederate Colonel J. Russell Butler's 1st (3rd) Kentucky Cavalry Regiment at the entrance of the gap. After skirmishing briefly and withdrawing under pressure, the rebels were unable to reach the gap before the better-fed horses of the Lightning Brigade. The Kentuckians fell apart as a unit and, unluckily for the Confederates, failed in their cavalry mission to provide intelligence of the Union movement to their higher headquarters. Although Wilder's main infantry support was well behind his mounted brigade and his division commander Major General Joseph J. Reynolds had directed him to fall back to the main force after contact, he determined to continue pushing through to seize and hold the Gap before the Confederate reinforcements could prevent him. The brigade drove the 1st Kentucky through the entire seven mile length of Hoover's Gap. At the other end, they were met with artillery fire and found out that the brigade and its one battery were outnumbered four-to-one. The brigade had met Brig. Gen. William B. Bate's brigade of Maj. Gen. Alexander P. Stewart's division.
Wilder entrenched on the hills south of the gap and determined to hold this extremely advanced position. Bate's brigade, supported by Brig. Gen. Bushrod Johnson's brigade and some artillery, assaulted Wilder's position, but was driven back by the concentrated fire of the Spencers, losing 146 killed and wounded (almost a quarter of his force) to Wilder's 61. Due to the heavy volume of fire he received from the brigade, Bate initially thought he was outnumbered five-to-one.
Colonel James Connolly, commander of the 123rd Illinois, wrote: