http://en.wikipedia.org/wiki/Franklin-N ... e_Campaign
A good primer from Wiki
The Franklin-Nashville Campaign, also known as Hood's Tennessee Campaign, was a series of battles in the Western Theater, conducted from September 18 to December 27, 1864,[1] in Alabama, Tennessee, and northwestern Georgia during the American Civil War. The Confederate Army of Tennessee under Lt. Gen. John Bell Hood drove north from Atlanta, threatening Maj. Gen. William T. Sherman's lines of communications and central Tennessee. After a brief attempt to pursue Hood, Sherman returned to Atlanta and began his March to the Sea, leaving Union forces under Maj. Gen. George H. Thomas to deal with Hood's threat.
Lt. Col Elkin
Chief Engineer AoT