Which of the serious defeats for the Union came first in the American Civil War: the Battle of Chickamauga or the Battle of Fredericksburg?
Battle of Chickamauga 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.
Battle of Hoover's Gap The Battle of Hoover's Gap (24 June 1863) was the principal battle in the Tullahoma Campaign of the American Civil War, in which Union General William S. Rosecrans drove General Braxton Bragg’s Confederates out of Central Tennessee. Rosecrans’ feigned move on the western end of the Confederate line had left the eastern mountain passes lightly defended, and Colonel John T. Wilder's mounted infantry achieved total surprise when they attacked Hoover's Gap. Success was attributed both to Rosecrans’ brilliant deception tactics and the high morale of Wilder’s ‘Lightning Brigade’, equipped with the new Spencer repeating rifle, which totally disoriented the enemy.