General William Tecumseh Sherman was appointed commander of the Military Division of Mississippi, including the Army of Tennessee, marking a crucial turning point in the American Civil War. His appointment led to revolutionary changes in military tactics and strategy.

General William Tecumseh Sherman's appointment to command the Union Army of Tennessee marked a pivotal moment in the American Civil War. His elevation to this crucial position in 1864 would prove instrumental in securing Union victory and forever changing the nature of modern warfare.

The decision to appoint Sherman came at a critical juncture when President Abraham Lincoln needed an aggressive and capable leader to take control of Union forces in the Western Theater. Following Ulysses S. Grant's promotion to General-in-Chief of all Union armies in March 1864, Sherman emerged as the natural choice to lead the Army of Tennessee. His previous successes in the Western campaigns and his close working relationship with Grant made him the ideal candidate for this vital command position.

William Tecumseh Sherman entered the Civil War as a colonel of the 13th U.S. Infantry Regiment in 1861. His progression through military ranks demonstrated his growing tactical expertise and leadership capabilities.

Sherman served as a superintendent at the Louisiana State Seminary before joining the Union Army in May 1861. His first major command came at the Battle of Bull Run, where he led a brigade of volunteers. After a brief period in Kentucky, where he accurately predicted the need for 200,000 troops to secure the region, Sherman received command of the District of Cairo in early 1862.

Key Early Assignments:

• Colonel of 13th U.S. Infantry Regiment (May 1861)
• Brigade Commander at Bull Run (July 1861)
• Department of the Cumberland Commander (October 1861)
• District of Cairo Commander (February 1862)

Sherman's military prowess emerged during the Vicksburg Campaign of 1862-1863. Under Grant's overall command, Sherman led the XV Corps through multiple successful operations.

Campaign Achievements:

• Captured Arkansas Post with 5,000 Confederate prisoners
• Led successful diversionary attacks at Chickasaw Bluffs
• Commanded troops in the final siege operations
• Secured Jackson, Mississippi during the campaign

Battle	Date	Union Troops	Result
Arkansas Post	January 1863	32,000	Victory
Chickasaw Bluffs	December 1862	30,000	Strategic Value
Siege of Vicksburg	May-July 1863	77,000	Victory

Major changes in Union Army leadership during early 1864 created opportunities for command restructuring in the Western Theater. These changes directly influenced Sherman's elevation to command the Army of Tennessee.

President Lincoln promoted Ulysses S. Grant to Lieutenant General on March 2, 1864, making him General-in-Chief of all Union armies. Grant's elevation left a crucial vacancy in the Western Theater, where he had previously commanded the Military Division of the Mississippi. His new role required him to relocate to Washington D.C. to oversee operations across all theaters of war.

The Military Division of Mississippi encompassed a vast territory from the Appalachian Mountains to the Mississippi River. This command included three armies:

• The Army of the Cumberland under General George Thomas
• The Army of the Tennessee under General James McPherson
• The Army of the Ohio under General John Schofield

Grant recommended Sherman for this position based on:

• Their successful collaboration during the Vicksburg Campaign
• Sherman's demonstrated ability to coordinate multiple army movements
• His proven strategic understanding of the Western Theater's geography
• His effective leadership of XV Corps operations in 1863

Date	Event
March 2, 1864	Grant promoted to Lieutenant General
March 12, 1864	Grant assumes General-in-Chief position
March 18, 1864	Sherman takes command of Military Division of Mississippi

General William Tecumseh Sherman assumed leadership of the Army of Tennessee in October 1863, marking a pivotal transition in Union military command structure. This appointment preceded his later elevation to command the entire Military Division of the Mississippi in March 1864.

The Army of Tennessee transferred from General William Rosecrans to Sherman following the Confederate victory at Chickamauga on September 20, 1863. President Lincoln relieved Rosecrans of command on October 16, 1863, citing his inability to pursue Confederate forces effectively after the Battle of Chickamauga. General George Thomas temporarily held command of the Army of Cumberland during this transition period, establishing defensive positions around Chattanooga.

Sherman's appointment catalyzed significant changes in the Union command structure across the Western Theater. The reorganization included:

• Integration of three XV Corps divisions from the Vicksburg Campaign
• Establishment of new supply lines through Nashville
• Creation of specialized cavalry units for reconnaissance operations
• Consolidation of artillery battalions at the corps level
• Formation of pioneer brigades for engineering operations

Command Changes	Date	Location
Rosecrans Relieved	October 16, 1863	Chattanooga
Thomas Interim Command	October 16-19, 1863	Chattanooga
Sherman Assumes Command	October 19, 1863	Memphis
XV Corps Integration	October 24, 1863	Chattanooga Area

Sherman immediately implemented tactical reforms focusing on mobility and supply efficiency. His command restructuring emphasized coordination between infantry divisions and established clear chains of command at corps and division levels.

Sherman faced immediate operational challenges upon assuming command of the Union Army of Tennessee in March 1864. His first priorities centered on reorganizing the army's structure and addressing critical supply line issues that had hampered previous operations.

Sherman's forces played a crucial role in breaking the Confederate siege of Chattanooga in November 1863. The Army of Tennessee executed a successful assault on Missionary Ridge, coordinating with other Union forces to drive Confederate General Braxton Bragg's army from their positions. The operation included:

• Capturing strategic positions along Lookout Mountain

• Coordinating attacks with George Thomas's Army of the Cumberland

• Securing supply routes through the "Cracker Line" to feed 40,000 troops

• Establishing forward bases for future operations into Georgia

• Consolidated 100,000 troops into three armies: Cumberland, Tennessee Ohio

• Established four major supply depots at Nashville Chattanooga Knoxville Rome

• Created mobile field hospitals with 3,000 medical personnel

• Streamlined logistics by reducing wagon trains to essential supplies

• Reorganized cavalry units into dedicated reconnaissance divisions

• Implemented a telegraph network connecting all major command posts

Army Component	Troop Strength	Supply Wagons	Artillery Pieces
Army of the Cumberland	60,000	800	130
Army of the Tennessee	25,000	400	96
Army of the Ohio	15,000	300	64

Sherman's appointment as commander of the Union Army of Tennessee marked a pivotal shift in the Civil War's Western Theater operations. His leadership revolutionized military tactics and reshaped the army's organizational structure.

Sherman's appointment strengthened the Union's position through three key innovations. His implementation of coordinated multi-army movements enabled simultaneous attacks across multiple fronts. His deep-strike strategy targeted Confederate infrastructure, including railroads, factories, and warehouses. The establishment of mobile supply bases increased the army's operational range to 300 miles from its primary depots.

Strategic Innovation	Impact on Union Operations
Multi-army Coordination	Enabled attacks on 3-4 fronts simultaneously
Deep-strike Operations	Destroyed 380 miles of Confederate rail lines
Mobile Supply Bases	Extended operational range to 300 miles

The Army of Tennessee underwent significant structural changes under Sherman's command. He reorganized 100,000 troops into three distinct operational units: the Army of the Cumberland, the Army of the Ohio, and the Army of the Tennessee. The implementation of corps-level logistics systems improved supply distribution efficiency by 40%. Sherman's reforms included:

• Creation of specialized cavalry reconnaissance units
• Integration of field artillery at division level
• Establishment of mobile field hospitals within 5 miles of combat zones
• Formation of dedicated engineer battalions for infrastructure operations
• Implementation of standardized communication protocols across all units

These organizational changes enhanced the army's combat effectiveness through improved coordination, faster response times, and superior battlefield intelligence gathering capabilities.

• Sherman was appointed commander of the Army of Tennessee in October 1863, following General Rosecrans' removal after the Battle of Chickamauga
• His appointment came at a critical time when President Lincoln needed an aggressive leader, leading to his later elevation to command the entire Military Division of Mississippi in March 1864
• Sherman's selection was influenced by his successful military career, including his leadership during the Vicksburg Campaign and close working relationship with General Grant
• Upon taking command, Sherman implemented major reforms including reorganizing 100,000 troops into three armies, establishing new supply lines, and creating specialized cavalry units
• His appointment proved pivotal for the Union's success, as he revolutionized military tactics through deep-strike strategy and extended operational capabilities up to 300 miles from supply bases

Sherman's appointment to command the Union Army of Tennessee in 1864 proved to be a turning point in the Civil War. His innovative military strategies revolutionized warfare tactics and significantly strengthened the Union's position in the Western Theater. Through organizational reforms efficient supply management and coordinated multi-army movements Sherman transformed a collection of separate units into a cohesive fighting force.

The success of his leadership went far beyond tactical victories. His appointment demonstrated President Lincoln's shrewd judgment in selecting commanders and highlighted the importance of having the right leader at the right time. Sherman's legacy of military innovation and organizational reform continues to influence military doctrine today.