Because of Tennessee’s strategic location, both the Union and the Confederacy fought fiercely over the state. Indeed, Tennessee’s position in the Upper South led President Abraham Lincoln to characterize the state as “the keystone of the Southern arch.” The state linked the Eastern Theater of the war with the Mississippi River and early became a natural offensive target for the Federal armies. Both sides sought to control Tennessee's rich resources, especially the state's rail and river routes. In the end, approximately 2,900 military engagements were fought on Tennessee soil; only the state of Virginia saw more armed conflicts during the Civil War. In addition to the sheer number of battles and skirmishes, Tennessee was the site of some of the bloodiest fighting of the war, as devastating battles took place at Shiloh, Stones River, and Franklin.
Just eight months after becoming the last state to leave the Union, Tennessee became the first to fall to Federal troops. Early in February 1862, Union troops quickly captured Forts Henry and Donelson on the Tennessee and Cumberland rivers. These successes left the capital of Nashville vulnerable, and Confederate forces abandoned the city. President Lincoln named Andrew Johnson, the only southerner to choose to remain in the U.S. Senate after secession, as military governor of Tennessee.
After the occupation of Nashville, the Union Army sought to improve its supply lines by extending the Nashville and Northwestern Railroad from Kingston Springs to the Tennessee River. The Federals impressed free blacks and escaped slaves to perform the labor associated with the extension, and in 1863 many of these men became soldiers in the United State Colored Troops. As such, they continued to not only build the rail line but to erect and man fortifications for its defense. In all, more than 20,000 African-Americans from Tennessee fought for the Union. The state ranked third in the supply of United States Colored Troops.
In November 1864, Confederate troops in Tennessee experienced one of their most distinctive military victories in the state, as well as one of their most devastating battles. Cavalry under Major General Nathan Bedford Forrest destroyed the Union depot at Johnsonville on the Tennessee River, the only time in the war that a cavalry force destroyed a naval depot. Although the battle had little effect on the outcome of the war, it is remembered for demonstrating Forrest’s tactical prowess. Later that month at Franklin, General John Bell Hood’s troops were eviscerated during a frontal attack on Union breastworks. The Confederates suffered more than three times as many casualties as the Federals, including the loss of six generals.
Shiloh, Fort Donelson, Chickamauga/Chattanooga, and Stones Rivers are significant Tennessee battles now interpreted by the National Park Service as National Military Parks. Tennessee State Parks has preserved the Civil War battlefields at Fort Pillow and Johnsonville. Stories of these conflicts and the people who fought them weave together the powerful chronicle that is the Civil War in Tennessee.
In the end, 64,333 Confederate soldiers and 58,521 Union soldiers perished in Tennessee, representing a total number of battle casualties of 122,854.