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.

The Army of the Tennessee was a Union army in the Western Theater of the American Civil War, named for the Tennessee River. A 2005 study of the army states that it "was present at most of the great battles that became turning points of the war—Fort Donelson, Vicksburg, and Atlanta" and "won the decisive battles in the decisive theater of the war."