Western theater of the American Civil War


The western theater of the American Civil War encompassed major military operations in the states of Alabama, Georgia, Florida, Mississippi, North Carolina, Kentucky, South Carolina and Tennessee, as well as Louisiana east of the Mississippi River. Operations on the coasts of these states, except for Mobile Bay, are considered part of the lower seaboard theater. Most other operations east of the Appalachian Mountains are part of the eastern theater. Operations west of the Mississippi River took place in the trans-Mississippi theater.
The western theater served as an avenue of military operations by Union armies directly into the agricultural heartland of the South via the major rivers of the region. The Confederacy was forced to defend an enormous area with limited resources. Most railroads ran from north to south, as opposed to east to west, making it difficult to send Confederate reinforcements and supplies to troops further from the more heavily populated and industrialized areas of the eastern Confederacy.
Union operations began in September 1861 with attempts to secure Kentucky, as more than half of the state was under Confederate control by late 1861 into 1862. Maj. Gen. Ulysses S. Grant's Army of the Tennessee had early successes in Kentucky and western Tennessee in 1861 and 1862, capturing the important strategic locations of Forts Henry and Donelson. The Army of the Tennessee and the Army of the Ohio defeated the Confederate Army of Mississippi, commanded by General Albert Sidney Johnston, at the Battle of Shiloh, driving it out of western Tennessee and subsequently marching into Mississippi and capturing Corinth. Grant's troops marched towards and captured Vicksburg in 1862–1863. Meanwhile, the Army of the Ohio experienced success, blocking a Confederate invasion of Kentucky and gaining control over large amounts of Tennessee through the Battle of Stones River and the 1863 Tullahoma Campaign while fighting against the Confederate Army of Tennessee, whose commander, Braxton Bragg, was often criticized for a perceived lack of military skill.
The Union army was briefly checked in its invasion of Georgia at the Battle of Chickamauga, and besieged at Chattanooga. Grant, now commanding the newly created Military Division of the Mississippi, took command, and received reinforcements from the Army of the Tennessee, as well as from the eastern Army of the Potomac. The siege of Chattanooga was lifted in November 1863. Following his elevation by Abraham Lincoln to General-in-Chief, Grant put Maj. Gen. William Tecumseh Sherman in charge of the combined armies. Chattanooga served as a launching pad for Sherman to capture the Confederate rail-hub of Atlanta and to march to the Atlantic, inflicting a major logistical and psychological blow to the Confederacy. After reaching the ocean, Sherman invaded the Carolinas. Operations in the western theater concluded with the surrender of Southern forces to the Union armies in North Carolina and Florida in May 1865 following General Robert E. Lee's surrender to Grant at Appomattox Court House.
The western theater typically receives less attention than the eastern theater. This has much to do with the greater proximity of action in the east to capitals and to major population centers. However, some historians consider it the war's most important theater. While the eastern theater essentially remained in stalemate until 1864, Union troops in the west, beginning in 1861, were able to steadily surround and drive back the Confederate troops, forcing them into eventual capitulation. This was done through a steady series of Union victories in major battles, interrupted by only a single defeat, which took place at Chickamauga.

Theater of operations

The western theater was an area defined by both geography and the sequence of campaigning. It originally represented the area east of the Mississippi River and west of the Appalachian Mountains. It excluded operations against the Gulf Coast and the Eastern Seaboard, but as the war progressed and William Tecumseh Sherman's Union armies moved southeast from Chattanooga, Tennessee in 1864 and 1865, the definition of the theater expanded to encompass their operations into Georgia and the Carolinas.
The West was by some measures the most important theater of the war. Capture of the Mississippi River has been one of the key tenets of Union General-in-Chief Winfield Scott's Anaconda Plan. Military historian J. F. C. Fuller has described the Union invasion as an immense turning movement, a left wheel that started in Kentucky, headed south down the Mississippi River, and then east through Tennessee, Georgia, and the Carolinas. With the exception of the Battle of Chickamauga and some daring raids by cavalry or guerrilla forces, the four years in the West marked a string of almost continuous defeats for the Confederates; or, at best, tactical draws that eventually turned out to be strategic reversals. Union generals consistently outclassed most of their Confederate opponents, with the exception of cavalry commander Nathan Bedford Forrest. As the war progressed, many Union officers in the Western Theater began to view emancipation as a practical strategy to weaken the Confederacy by depriving it of its labor force and bolstering Union troop numbers with formerly enslaved individuals. This pragmatic approach to emancipation played a significant role in Union military policy in the region. Lacking the proximity to the opposing capitals and population centers of the East, the astounding Confederate victories, and the fame of Eastern generals such as Robert E. Lee, George B. McClellan, and Stonewall Jackson, the western theater received considerably less attention than the Eastern, both at the time and in subsequent historical accounts. The near-steady progress that Union forces made in defeating Confederate armies in the West and overtaking Confederate territory went nearly unnoticed. Beyond conventional Union and Confederate battles, the Western Theater was also shaped by conflicts with Native American nations, federal efforts to control slavery in Western territories, and struggles over political allegiance in border regions.
The campaign classification established by the United States National Park Service is more fine-grained than the one used in this article. Some minor NPS campaigns have been omitted and some have been combined into larger categories. Only a few of the 117 battles the NPS classifies for this theater are described. Boxed text in the right margin show the NPS campaigns associated with each section.

Principal Union commanders of the western theater

Principal Confederate commanders of the western theater

Early operations (June 1861 – January 1862)

The focus early in the war was on two critical states: Missouri and Kentucky. The loss of either would have been a crippling blow to the Union cause. Primarily because of the successes of Captain Nathaniel Lyon and his victory at Boonville in June, Missouri was held in the Union. The state of Kentucky, with a pro-Confederate governor and a pro-Union legislature, had declared neutrality between the opposing sides. This neutrality was first violated on September 3, when Confederate Maj. Gen. Leonidas Polk occupied Columbus, considered key to controlling the Lower Mississippi. Two days later Union Brig. Gen. Ulysses S. Grant, displaying the personal initiative that would characterize his later career, seized Paducah. Henceforth, neither adversary respected the proclaimed neutrality of the state; while most of the state government remained loyal to the Union, the pro-Confederate elements of the legislature organized a separate government in Russellville that was admitted into the Confederate States. This sequence of events is considered a victory for the Union because Kentucky never formally sided with the Confederacy, and if the Union had been prevented from maneuvering within Kentucky, its later successful campaigns in Tennessee would have been more difficult.
On the Confederate side, General Albert Sidney Johnston commanded all forces from Arkansas to the Cumberland Gap. He was faced with the problem of defending a broad front with numerically inferior forces, but he had an excellent system of lateral communications, permitting him to move troops rapidly where they were needed, and he had two able subordinates, Polk and Maj. Gen. William J. Hardee. Johnston also gained political support from secessionists in central and western counties of Kentucky via a new Confederate capital at Bowling Green, set up by the Russellville Convention. The alternative government was recognized by the Confederate government, which admitted Kentucky into the Confederacy in December 1861. Using the rail system resources of the Mobile and Ohio Railroad, Polk was able to quickly fortify and equip the Confederate base at Columbus.
The Union military command in the West, however, suffered from a lack of unified command, organized by November into three separate departments: the Department of Kansas, under Maj. Gen. David Hunter, the Department of the Missouri, under Maj. Gen. Henry Halleck, and the Department of the Ohio, under Brig. Gen. Don Carlos Buell. By January 1862, this disunity of command was apparent because no strategy for operations in the Western theater could be agreed upon. Buell, under political pressure to invade and hold pro-Union East Tennessee, moved slowly in the direction of Nashville, but achieved nothing more substantial toward his goal than minor victories at Middle Creek under Col. James A. Garfield and Mill Springs under Brig. Gen. George Henry Thomas. In Halleck's department, Grant demonstrated down the Mississippi River by attacking the Confederate camp at Belmont to divert attention from Buell's intended advance, which did not occur. On February 1, 1862, after repeated requests by Grant, Halleck authorized Grant to move against Fort Henry on the Tennessee.