At last Sherman is before Atlanta. The photograph shows one of the keypoints in the Confederate defense, the fort at the head of Marietta Street, toward which the Federal lines were advancing from the northwest. The old Potter house in the background, once a quiet, handsome country seat, is now surrounded by bristling fortifications, palisades, and double lines of _chevaux-de-frise_. Atlanta was engaged in the final grapple with the force that was to overcome her. Sherman has fought his way past Kenesaw and across the Chattahoochee, through a country which he describes as "one vast fort," saying that "Johnston must have at least fifty miles of connected trenches with abatis and finished batteries." Anticipating that Sherman might drive him back upon Atlanta, Johnston had constructed, during the winter, heavily fortified positions all the way from Dalton. During his two months in retreat the fortifications at Atlanta had been strengthened to the utmost. What he might have done behind them was never to be known. [Illustration: THE CHATTAHOOCHEE BRIDGE] "One of the strongest pieces of field fortification I ever saw"--this was Sherman's characterization of the entrenchments that guarded the railroad bridge over the Chattahoochee on July 5th. A glimpse of the bridge and the freshly-turned earth in 1864 is given by the upper picture. At this river Johnston made his final effort to hold back Sherman from a direct attack upon Atlanta. If Sherman could get successfully across that river, the Confederates would be compelled to fall back behind the defenses of the city, which was the objective of the campaign. Sherman perceived at once the futility of trying to carry by assault this strongly garrisoned position. Instead, he made a feint at crossing the river lower down, and simultaneously went to work in earnest eight miles north of the bridge. The lower picture shows the canvas pontoon boats as perfected by Union engineers in 1864. A number of these were stealthily set up and launched by Sherman's Twenty-third Corps near the mouth of Soap Creek, behind a ridge. Byrd's brigade took the defenders of the southern bank completely by surprise. It was short work for the Federals to throw pontoon bridges across and to occupy the coveted spot in force. [Illustration: INFANTRY AND ARTILLERY CROSSING ON BOATS MADE OF PONTOONS COPYRIGHT, 1911, REVIEW OF REVIEWS CO.]