As the autumn drew on Grant was left at Corinth, by no fault of his own but because of Halleck's orders, with a force barely sufficient, if sufficient at all, to hold the railroads and outlying posts which he was set to guard. In his front there lay a threatening army stronger than any that he could hope to bring together at any one point. To the eastward Buell, under paralyzing orders, was slowly marching toward Chattanooga, while Bragg with a strong Confederate army was hastening northward to seize that commanding strategic position and to push thence northward with high hopes and fair prospects of making the Ohio river before the year was out, the dividing line between the Northern and Southern forces, replacing the line which by Grant's successes had been drawn the whole width of two states further south. On these points the testimony of General Grant is too direct, too conclusive and too valuable to be omitted here, or to be given otherwise than in his own carefully chosen words. On page 237 _et seq._ of the "Memoirs" he writes: General Buell had left Corinth about the tenth of June to march upon Chattanooga. Bragg, who had succeeded Beauregard in command, sent one division from Tupelo on the twenty-seventh of June for the same place. This gave Buell about seventeen days' start. If he had not been required to repair the railroad as he advanced, the march could have been made in eighteen days at the outside, and Chattanooga must have been reached by the national forces before the rebels could have possibly got there. On page 240 we have this careful estimate of the situation at the beginning of September: