The Battle of Chickamauga, fought on September 18–20, 1863 between Union and Confederate forces in the American Civil War, marked the end of a Union offensive in southeastern Tennessee and northwestern Georgia — the Chickamauga Campaign. It was the first major battle of the war fought in Georgia, the most significant Union defeat in the Western Theater, and involved the second-highest number of casualties after the Battle of Gettysburg.The battle was fought between the Army of the Cumberland under Maj. Gen. William Rosecrans and the Confederate Army of Tennessee under Gen. Braxton Bragg, and was named for Chickamauga Creek, which meanders near the battle area in northwest Georgia (and ultimately flows into the Tennessee River about 3.5 miles (5.6 km) northeast of downtown Chattanooga).
