Following the Battle of Resaca, May 13-15, Gen. Joseph E. Johnston’ s army retreated southward while Sherman pursued. Failing to find a good defensive position south of Calhoun, Johnston continued to Adairsville while the Rebel cavalry fought a skillful rearguard action.

After the fall of Atlanta, Hood moved northward to threaten the Western & Atlantic Railroad, Sherman’s supply line. He attacked a number of minor garrisons and damaged track during October 2-4. Sherman sent reinforcements—John M. Corse’s brigade—to Allatoona just before the Rebels attacked there. Maj. Gen. Samuel G. French’s Confederate division arrived near Allatoona at sunrise on the 5th.

Following the Battle of Peachtree Creek, Hood determined to attack Maj. Gen. James B. McPherson’s Army of the Tennessee. He withdrew his main army at night from Atlanta’ s outer line to the inner line, enticing Sherman to follow. In the meantime, he sent William J. Hardee with his corps on a fifteen-mile march to hit the unprotected Union left and rear, east of the city.

As Sherman’s infantry marched southeast through Georgia, his cavalry, under Brig. Gen. Judson Kilpatrick moved northeastward, on November 24, 1864, to destroy the railroad midway between Augusta and Millen, burn the trestle near Briar Creek and, if possible, release Union prisoners confined at Camp Lawton, near Millen, while feigning a drive towards Augusta. Confederate Maj. Gen. Joseph Wheeler was fooled and concentrated his cavalry forces around Augusta.

After the Tullahoma Campaign, Rosecrans renewed his offensive, aiming to force the Confederates out of Chattanooga. The three army corps comprising Rosecrans’ s army split and set out for Chattanooga by separate routes. In early September, Rosecrans consolidated his forces scattered in Tennessee and Georgia and forced Bragg’s army out of Chattanooga, heading south.

Johnston’s army fell back from the vicinity of Cassville-Kinston, first to Allatoona Pass and then to the Dallas area and entrenched. Sherman’s army tested the Rebel line while entrenching themselves. The Battle of Dallas occurred on May 28 when Lt. Gen. William J. Hardee’s corps probed the Union defensive line, held by Maj. Gen. John A. Logan’s Army of the Tennessee corps, to exploit any weakness or possible withdrawal.

From Vicksburg, Mississippi, Sherman launched a campaign to take the important railroad center at Meridian and, if the situation was favorable, to push on to Selma and threaten Mobile, in order to prevent the shipment of Confederate men and supplies. To counter the threat, Confederate President Jefferson Davis ordered troops into the area.

Maj. Gen. Joseph Wheeler and his cavalry raided into North Georgia to destroy railroad tracks and supplies. They approached Dalton in the late afternoon of August 14 and demanded the surrender of the garrison. The Union commander, Col. Bernard Laibolt, refused to surrender and fighting ensued.

After the Tullahoma Campaign, Rosecrans renewed his offensive, aiming to force the Rebels out of Chattanooga. The three corps comprising Rosecrans’s army split and set out for Chattanooga by separate routes. Hearing of the Union advance, Braxton Bragg concentrated troops around Chattanooga.

Earlier, Maj. Gen. William T. Sherman’s forces had approached Atlanta from the east and north. Hood had not defeated them, but he had kept them away from the city. Sherman now decided to attack from the west. He ordered the Army of the Tennessee, commanded by Maj. Gen. O.O. Howard, to move from the left wing to the right and cut Hood’s last railroad supply line between East Point and Atlanta.

Rear Adm. Samuel F. Du Pont [US] ordered three ironclads, Patapsco, Passaic, and Nahant, to test their guns and mechanical appliances and practice artillery firing by attacking Fort McAllister, then a small three-gun earthwork battery. On March 3, 1863, the three ironclads conducted an eight-hour bombardment.

As Sherman’ s troops approached Savannah they sorely required supplies. Sherman determined that if he could take Fort McAllister, supply ships could reach him. Thus, he ordered Maj. Gen. O.O. Howard, commander of his right wing, to take the fort.

Fort Pulaski, built by the U.S. Army before the war, is located near the mouth of the Savannah River, blocking upriver access to Savannah. Fortifications such as Pulaski, called third system forts, were considered invincible, but the new technology of rifled artillery changed that.

Brig. Gen. Charles Walcutt was ordered to make a demonstration, with the six infantry regiments and one battery that comprised his brigade, toward Macon to ascertain the disposition of enemy troops in that direction.

Sherman had successfully cut Hood’s supply lines in the past by sending out detachments, but the Confederates quickly repaired the damage. In late August, Sherman determined that if he could cut Hood’s supply lines—the Macon & Western and the Atlanta & West Point Railroads—the Rebels would have to evacuate Atlanta.

On the night of June 18-19, Gen. Joseph E. Johnston, fearing envelopment, withdrew his army to a new, previously selected position astride Kennesaw Mountain. This entrenched arc-shaped line, to the north and west of Marietta, protected the Western & Atlantic Railroad, the supply link to Atlanta.

On the night of June 18-19, Gen. Joseph E. Johnston, fearing envelopment, moved his army to a new, previously selected position astride Kennesaw Mountain, an entrenched arc-shaped line to the west of Marietta, to protect his supply line, the Western & Atlantic Railroad. Having encountered entrenched Rebels astride Kennesaw Mountain stretching southward, Sherman fixed them in front and extended his right wing to envelop their flank and menace the railroad.

While Confederate Maj. Gen. Joseph Wheeler was absent raiding Union supply lines from North Georgia to East Tennessee, Maj. Gen. William Sherman, unconcerned, sent Judson Kilpatrick to raid Rebel supply lines. Leaving on August 18, Kilpatrick hit the Atlanta & West Point Railroad that evening, tearing up a small area of tracks.

During the Atlanta Campaign, Sherman maneuvered Johnston's Confederate army out of several successive defensive positions in Cobb County. This strategy spared the Union army from making costly frontal attacks on the well-situated Confederates.

After Johnston retreated to Allatoona Pass on May 19-20, Sherman decided that he would most likely pay dearly for attacking Johnston there, so he determined to move around Johnston’s left flank and steal a march toward Dallas.