The success won by Schofield at Olley’s Creek indicated the direction for the next Federal movement. Sherman quickly decided to shift troops to his right, knowing that such a move would force Johnston to choose between giving up the Kennesaw line or being cut off from Atlanta. Accordingly, he began to reinforce Schofield by moving McPherson from the left to the right. By the afternoon of July 2, Federal troops were pushing southward on Sandtown Road against only light opposition from small Confederate detachments. Johnston was aware of what was happening—in fact, he had expected such a movement since the failure of the assault on the 27th. Believing that it would be unwise to stretch his lines further and realizing that the troops opposing the Federal advance could do no more than delay it, Johnston decided to abandon his Kennesaw Mountain position and fall back to a previously prepared line near Smyrna, 4 miles to the south. Accordingly, during the night of July 2-3, the Confederates filed out of their trenches around Marietta and marched southward. When Sherman discovered that the Southerners were gone, he pushed forward in pursuit, hoping to strike while the enemy was retreating. In the late afternoon of the 3d, the Northerners reached the new Confederate line. The 4th was spent in skirmishing, but before a serious battle could develop, the Federal right secured a strategic position from which it threatened to slice in between Johnston’s army and Atlanta. Again, the threat to his left forced Johnston to retreat. During the night of July 4-5, the Southerners fell back to a heavily fortified position on the north bank of the Chattahoochee. On the 5th, the Federals pushed forward until they reached the new Southern line. Skirmishing that day convinced Sherman that the position was too strong to be carried by a headlong assault. He dispatched a cavalry force to seize Roswell, an important little manufacturing town about 16 miles upriver from Johnston’s fortifications, and allowed his men a few days’ rest while he planned the next move. [Illustration: ACROSS THE CHATTAHOOCHEE RIVER] After carefully studying the situation, the Federal commander decided to attempt a crossing near the mouth of Soap Creek, above Johnston’s right flank. On July 8, he moved Schofield’s Army of the Ohio into position for the crossing. In a brilliant movement, Schofield, utilizing pontoon boats and the ruins of a submerged fish dam, got over the river and drove away the small group of Southerners defending the area. Other troops were rushed across, bridges were built, trenches were dug, and by nightfall the Northerners held a secure bridgehead on the southern bank. On the following day, the Federal cavalry got over the river at Roswell. Sherman had successfully crossed the last major barrier between Chattanooga and Atlanta and had carried the fighting into the open country south of the Chattahoochee where the terrain would favor him.