- Natural features of Chattanooga -- strategical importance -- relations to East Tennessee -- Chickamauga campaign -- defeat of Rosecrans -- retreat into Chattanooga -- abandonment of Lookout mountain -- investment of Chattanooga -- sufferings of army of the Cumberland -- Hooker sent west to support Rosecrans -- Burnside's movement into East Tennessee -- difficulties of supply -- Grant starts for Chattanooga -- directions to his three armies -- arrival at Chattanooga -- Thomas's magnanimity -- Lookout valley -- Brown's ferry -- plan of operations to recover Lookout valley -- seizure of Brown's ferry -- March of Hooker from Bridgeport -- battle of Wauhatchie -- repulse of rebels -- Lookout valley secured -- communication reopened -- elation of soldiers -- further difficulties in supply -- Sherman's March from Memphis -- long lines of communication -- Sherman's magnanimity -- Grant hurries Sherman -- alarming situation of Burnside -- anxiety of government -- Grant's calmness -- Longstreet moves against Burnside -- Grant's counter-plan -- dispatches of Grant to Halleck and Burnside -- Thomas ordered to attack Bragg -- Thomas not Brady -- movement postponed till Sherman's arrival -- great anxiety about Burnside -- road from Nashville to Decatur opened -- supplies ordered to Burnside by Cumberland river -- difficulties of Sherman's route -- critical condition of Grant's armies -- extent of his operations -- Halleck still anxious about Burnside -- Grant impresses on Burnside necessity of holding out -- confidence of Burnside -- arrival of Sherman at Bridgeport -- reconnoissance by Grant, Sherman, and Thomas -- orders issued for battle of Chattanooga.
The Cumberland mountains constitute the natural boundary between what are called the cotton states —the semi-tropical region of the American Union—and the vast grain-growing plains of Kentucky and Tennessee. Several important ranges cluster just where the three great states of Tennessee, Georgia, and Alabama approach nearest to each other; the  mountains crowding close, as if to watch the scene where the destinies of mountains and states were both to be decided. From some of the highest points in this vicinity the territory of seven different states can be distinctly seen. Here, also, the Tennessee river breaks through from the east, hemmed in at times on every hand, but making the mountains give it room, and, forcing its way in a hundred windings, until, at last, it eludes or overcomes every barrier, and finds a passage to more western fields. At one of the most abrupt of all its angles, the hills recede so as to leave an open but uneven space, not more than five or six miles square, bounded on the north by the Tennessee, begirt on every side with rugged peaks, and guarded on the west by a grim and almost perpendicular height, that rises directly from the water's edge more than two thousand feet. This point was once the boundary and the barrier of the Indian country. The southern limit of the field is known as Missionary ridge, called so by the Indians, who allowed the missionaries to pass no further; a gorge in the mountains, opening south, is still named Rossville gap, after the famous Cherokee chief, John Ross; while the lofty crest that looks out over the rugged valley was called Chattanooga—the Eagle's Nest. The whole region was a mighty bulwark, covering one of the most important avenues for access to the South, between the Mississippi and the Atlantic coast. Away, at the centre of the continent, these precipitous heights, this lonely valley, and this tortuous stream seemed the very spot where the eagles might build their nests, and the aborigines pitch their camps, secure from the intruding step of the white  man. But, first, the Tennessee river itself tempted the adventurous pioneer; and, when the tide of trade and the growth of the republic could no longer be stayed, even the mountains were forced to open their gates. A railroad must be built, connecting the Mississippi with the Atlantic, and the only route through these almost inaccessible hills was along the valley of the Tennessee. Then, the South must be connected with its brother North; and the line of travel stretched out from Mobile, and all the great railways from the interior of the cotton region, from Mississippi, and Georgia, and Alabama, and South Carolina, centred at Atlanta, and reached up along one line, through ridges and ranges, penetrating them by tunnels when Nature afforded no pathway, until, under the shadow of the Chattanooga mountain, the junction with the great eastern line was formed. Where the railroads from Memphis and Charleston and Richmond and Nashville and Atlanta meet, a town sprang up, of course, and was named from the mountain at whose base it was built, Chattanooga; while the acclivity itself now received an English name, and was henceforth known as the Lookout mountain. When the rebellion broke out, it was at once perceived by military men that Chattanooga must become one of the important strategic positions of the war. The great railway lines converging here afforded the rebels immense opportunities for concentrating and supplying their armies—opportunities which were seized and enjoyed to their full extent. Connecting the extreme eastern and the western portions of the would-be confederacy, these roads enabled its authorities, again and again, to move troops with facility and promptness from one part of the theatre  of war to another, at some critical moment; and, for years, they furnished the principal route by which the eastern armies received their revenues of grain and beef, from the prolific regions of