George Henry Thomas was an American general in the Union Army during the American Civil War and one of the principal commanders in the Western Theater.

The Battle of Missionary Ridge, also known as the Battle of Chattanooga, was fought on November 25, 1863, as part of the Chattanooga campaign of the American Civil War. Following the Union victory in the Battle of Lookout Mountain on November 24, Union forces in the Military Division of the Mississippi under Maj. Gen. Ulysses S. Grant assaulted Missionary Ridge and defeated the Confederate Army of Tennessee, commanded by Gen. Braxton Bragg, forcing it to retreat to Georgia.