In the summer of 1864, Georgia was the scene of one of the most important campaigns of the Civil War. William Tecumseh Sherman's push southward toward Atlanta threatened the heart of the Confederacy, and Joseph E. Johnston and the Army of Tennessee were the Confederacy's best hope to defend it. In June, Johnston managed to grind Sherman's advance to a halt northwest of Atlanta at Kennesaw Mountain. After weeks of maneuvering, on June 27, Sherman launched a bold attack on Johnston's lines. The Confederate victory was one of the bloodiest days of the entire campaign. And while Sherman's assaults had a frightful cost, Union forces learned important lessons at Kennesaw Mountain that enabled the fall of Atlanta several months later.