Prelude to the Battle
Federal Breakout from Chattanooga
In late November 1863, Union forces commanded by Major General Ulysses S. Grant successfully lifted Confederate General Joseph E. Johnston’s siege of Chattanooga, Tennessee. Union victories at the Battle of Lookout Mountain (November 24) and the Battle of Missionary Ridge (November 25) forced Johnston to withdraw thirty miles south near Dalton, Georgia.
Grant Promoted to Lieutenant General
After the Federal breakout from Chattanooga, President Abraham Lincoln promoted Grant to the special rank of Lieutenant General and placed him in command of all Union armies. Grant moved his headquarters to Washington, leaving his trusted subordinate, Major General William T. Sherman, in command of federal operations in the western theater.
Grant’s Umbrella Strategy
Upon arriving in Washington, Grant, along with Sherman devised a “total war” policy aimed at the Confederate military, transportation systems, and anything else abetting the Rebel cause. Grant’s primary military strategy was a coordinated effort to attack and defeat the two main Confederate armies in the field, Robert E. Lee and the Army of Northern Virginia in the east, and Joseph E. Johnston and the Army of Tennessee in the west.
Grant Pursues Lee and Sherman Pursues Johnston
On May 5, 1864, Grant launched his Overland Campaign against Lee in Virginia. Two days later, Sherman led three armies, the Army of the Tennessee, commanded by Major General James B. McPherson; the Army of the Ohio, commanded by Major General John M. Schofield; and the Army of the Cumberland, commanded by Major General George H. Thomas, out of Tennessee in pursuit of Johnston’s army in northern Georgia.
May 7–13, 1864 — Clash at Rocky Face Ridge
On May 7, 1864, Sherman’s forces approached the Army of Tennessee, entrenched near Dalton in rugged, mountainous terrain on and around Rocky Face Ridge. For two days, General George Thomas’s Army of the Cumberland tested the Rebel defenses with limited gains.
Sherman Gets Around Johnston
Foreseeing little prospect for success through frontal assaults, Sherman sent General James McPherson’s Army of the Tennessee west, in search of a way around the Confederate defenders. On May 9, McPherson discovered an unprotected gap in the mountains at Snake Creek. Leaving Thomas to demonstrate before the main Confederate line, Sherman moved the rest of his army south through Snake Creek Gap, threatening to disable the Western and Atlantic Railroad behind Johnston’s lines.
In danger of being outflanked and having his supply line severed, Johnston withdrew twelve miles to Resaca, Georgia on the night of May 12–13.
Aftermath of the Battle
Although Sherman probably suffered higher casualties than Johnston (total casualties are unknown), the Battle of Rocky Ridge was a Union victory because Johnston yielded ground to Sherman’s seemingly inexorable drive toward Atlanta, Georgia.