Chattanooga served as a vital transportation hub connecting the eastern and western sectors of the Confederacy. In September of 1863, Confederate Braxton Bragg trapped Rosecrans and his Union forces inside of the city. With the aid of Joseph Hooker and Ulysses S. Grant, Union forces rallied for a key battle in November–which itself climaxed in the triumphant Northern attack on Missionary Ridge led by George H. Thomas.