Bragg relieved or reassigned the generals who had testified against him, and retaliated against Longstreet by reducing his command to only those units that he brought with him from Virginia. Despite the dysfunctional command climate under Bragg, and the lack of support from the War Department and President Davis concerning Bragg's removal, Longstreet did the best he could to continue to seek options in the Chattanooga Campaign. Bragg resigned himself and his army to the siege of the Union Army of the Cumberland in Chattanooga. At about this time, Longstreet learned of the birth of a son, who was named Robert Lee. Grant arrived in Chattanooga on October 23 and took overall command of the new Union Military Division of the Mississippi. He replaced Rosecrans with Thomas.