George Henry Thomas (July 31, 1816 – March 28, 1870) was a career United States Army officer and a Union General during the Civil War, becoming one of the principal commanders in the Western Theater and the hero of the Battle of Chickamauga.
Despite being a Southerner, Thomas chose to serve the Union during the Civil War. The Virginian served in important subordinate commands at Perryville and Stones River before his stout defense at the Battle of Chickamauga in 1863 saved the Union Army from being completely routed and earned him his most famous nickname, the "Rock of Chickamauga." He followed soon after with a dramatic breakthrough on Missionary Ridge in the Battle of Chattanooga. In the Franklin-Nashville Campaign of 1864, he achieved one of the most decisive victories of the war, destroying the army of Confederate General John Bell Hood, at the Battle of Nashville.
Thomas had a successful record in the Civil War, but he failed to achieve the historical acclaim of some of his contemporaries, including Ulysses S. Grant and William T. Sherman. He developed a reputation as a slow, deliberate general who shunned self-promotion and who turned down advancements in position when he did not think they were justified. After the war, he did not write memoirs to advance his legacy. He also had an uncomfortable personal relationship with Grant, which served him poorly as Grant advanced in rank and eventually to the presidency.
Days after the Battle of Chickamauga, Thomas wrote his official account of the battle, and it was preserved in The War of the Rebellion: Official Records of the Union and Confederate Armies. This edition of his account includes illustrations of the the battle's important generals.