Sherman broke loose from his railroad supply line in a large-scale sweep in an attempt to force Johnston's army to retreat from its strong position south of the Etowah River.

When the Union XX Corps under Major General Joseph Hooker tried to force its way through the Confederate lines at New Hope Church, its soldiers were stopped with heavy losses.

However, when Sherman's army crossed the Etowah River and attempted to move around Johnston's left flank, the Confederate general anticipated his opponent's intentions.

[2] The 25,000 non-combatants accompanying the army included railroad employees and repair crews, teamsters, medical staff, and Black camp servants.

Hood's corps included the divisions of Major Generals Thomas C. Hindman, Carter L. Stevenson, and Alexander P. Stewart.

[6] Sherman launched his campaign on May 7, 1864, with the Battle of Rocky Face Ridge during which he turned Johnston's western flank.

Schofield's corps passed through Cartersville and reached the Etowah to find the bridges burnt and the Confederates gone.

The Western and Atlantic Railroad ran through a gorge at Allatoona Pass and Johnston posted his army there in an extremely strong defensive position.

Since it would be leaving the railroad line, the army carried 20 days of supplies in its wagons and evacuated all its wounded and unfit men to the rear.

Sherman was anxious about his railroad supply line which ran 80 mi (129 km) back to Chattanooga.

Fearing the railroad might be damaged by Confederate cavalry raids, Sherman ordered Brigadier General John E. Smith's XV Corps division from Huntsville, Alabama, and nine XXIII Corps regiments from East Tennessee and Kentucky forward to guard the Western and Atlantic Railroad.

To replace these units, he summoned northern state governors to recruit 100-day regiments to garrison the rear area railroads.

[9] Sherman directed McPherson's two corps on his right wing to march from Kingston south to Van Wert and then east to Dallas.

Since Brigadier General Jefferson C. Davis' division (XIV Corps) was already to the west at Rome, it moved with McPherson.

Garrard's cavalry covered McPherson's wing, while McCook's horsemen scouted ahead of Thomas's center.

Avoiding Kilpatrick's cavalry, which was patrolling the area, Wheeler's horsemen captured 70 wagons and burned others.

Alerted by reports from Jackson's cavalry division, Johnston deduced that the Union army was maneuvering to turn his left flank.

That afternoon, McCook's horsemen captured a Confederate courier with a message that Johnston's army was moving toward Dallas.

Geary was compelled to deploy Colonel Charles Candy's brigade in an extended skirmish line in order to drive Jones' Confederates back.

[17] Having marched down the right fork toward Dallas, Williams' troops had to retrace their route to Owen's Mills, then turn right into the road Geary had taken.

[18] The 4,000 Confederate defenders belonged to Stewart's division, with the brigades of Brigadier Generals Marcellus Augustus Stovall, Henry D. Clayton, and Alpheus Baker in the front line, from left to right, and Brigadier General Randall L. Gibson's brigade in reserve.

[20] The Union generals hoped that their opponents would be caught in the open, but it became clear that the Confederates were protected by earth and log field fortifications.

He hoped that he was only facing Hood's corps, but it was finally beginning to dawn on him that Johnston's entire army was in front of him.

McPherson's wing and Davis' division occupied Dallas in the afternoon and established a position two miles farther east.