Battle of Chickamauga
The Battle of Chickamauga, fought on September 18–20, 1863, between U.S. and Confederate forces in the American Civil War, marked the end of a Union offensive, the Chickamauga Campaign, in southeastern Tennessee and northwestern Georgia. 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.