The Army of the Cumberland stormed Missionary Ridge

Grant ordered Thomas to advance in the center as a demonstration supporting Sherman, whose limited attacks had made little progress. Once the Army of the Cumberland captured the lower rifle pits, remaining there under fire was untenable, so units continued up the slope with local commanders following their men. Bragg's guns and infantry occupied the geographical rather than the military crest, leaving dead ground that protected parts of the climb and prevented effective support for the rifle pits below. Arthur MacArthur's flag-bearing action during the mass ascent earned him the Medal of Honor. Grant was furious that the troops had exceeded his order and feared the consequences if the assault failed, exposing the tension between centralized control and battlefield initiative. Hooker's movement through Rossville Gap then threatened the southern flank and helped turn the breakthrough into a collapse of Bragg's center.