During the United States Civil War, southwestern Virginia was mired in a bloody guerrilla conflict that involved Confederate irregular combatants defending the region from invading or raiding Union Army forces. Simmering for the entirety of the war, this conflict revolved around the Virginia and Tennessee Railroad (VandT), a critical railway that ran through southwestern Virginia and connected the southwestern Confederacy with Richmond and the rest of Virginia. As the war progressed, this railway moved increasingly large amounts of foodstuffs and minerals vital to the Confederate war effort, and by the later stages of the war it was the most important railway in the South. Union Army commanders in West Virginia recognized the incredible importance of the VandT to the Confederacy, and launched a multitude of major and minor invasions and raids into southwestern Virginia with the intent of crippling the railroad. Confederate partisan rangers, bushwhackers, and home guards played separate roles in weakening, distracting, and hampering Union Army operations in southwestern Virginia, thereby helping to defend the VandT from attacks. Their actions played a crucial role in ensuring the survival of the railroad until nearly the end of the war, and thus Confederate guerrillas had a strategic effect on the course of the war in southwestern Virginia. / Master of Arts / During the United States Civil War, Confederate guerrillas in southwestern Virginia played a critical role in the defense of the Virginia and Tennessee Railroad (V&T) in southwestern Virginia. The V&T ran from Bristol, Tennessee to Lynchburg, Virginia, and connected the fertile fields and mines of southwestern Virginia and the southwestern Confederacy with the rest of Virginia. The railroad proved to be one of the most critical transportation assets in the entire Confederacy, and thus it attracted the attention of Union armies in West Virginia who consistently tried to attack and cripple the railroad throughout the course of the war. Confederate guerrillas weakened, distracted, and hampered Union Army operations in southwestern Virginia, thereby helping to defend the V&T from assaults and enabling the railroad to survive until almost the very end of the conflict.