Major General John Dix ordered to take command of the Department of Maryland; Brigadier General William S. Rosecrans ordered to take command of the Department of the Ohio
William Rosecrans [US] beat Sterling Price [CS] who withdrew when scouts report a column under the command of Edward O. C. Ord was advancing from the Mississippi.
Earl Van Dorn [CS] and Sterling Price [CS] attack William Rosecrans [US] northern perimeter, driving it back to a reinforced line. Rosecrans successfully defends the city
Don Carlos Buell [US] is relieved of command from the Army of the Ohio for his failure to pursue Bragg [CS] following the Battle of Perryville. William Starke Rosecrans is ordered to replace him.
General Braxton Bragg [CS] tries to split General William Rosecrans [US] forces as they try to return to the safety of Chattanooga. A second day breakthrough at the Brotherton Cabin forces the federals into a retreat, halted only by the Rock of Chickamauga, General George Thomas on Snodgrass Hill
The bloodiest two days in American history cost the Federals 1,657 dead, 9,756 wounded, and 4,757 missing for a total of 16,170 casualties out of 58,000 troops. The Confederate losses were 2,312 dead, 14,674 wounded and 1,468 for a total of 18,545 out of 66,000 troops.
President Lincoln wires Gen. Rosecrans [US} in Chattanooga, telling him 40,000 to 60,000 troops are on their way. Within a week a corps arrives at Stevenson, Alabama