General Grant, at Corinth, had been pondering a great scheme which he meant to undertake so soon as his scanty army should be sufficiently reinforced. If Richmond had an artificial value as a token of final triumph, the Mississippi River had scarcely less value of a practical character. Vicksburg and Port Hudson cut out a mid-section of about 200 miles of the great stream, which section still remained under Confederate control. Vicksburg was General Grant's objective point. Even to conceive the capture of this stronghold seemed in itself evidence of genius; no mere pedant in warfare could have had the conception. Every difficulty lay in the way of the assailant. The Confederates had spared no skill, no labor, no expense in fortifying the town; yet after all had been done that military science could do, human achievement counted for little in comparison with the surpassing arrangements of Nature. If what she intended could be inferred from what she had done, she clearly had designed this town to be through all time a veritable "virgin fortress;" she had made for its resting-place a great bluff, which jutted insolently out into the channel of the Mississippi River, and upon the summit of which the cluster of buildings resembled rather an eyrie of eagles than a place of human habitation; the great stream, as if confounded by the daring obstruction, before it could recover its interrupted course spread itself far over the surrounding country in a tangle of bayous and a vast expanse of unwholesome, impassable swamp; the high ridges which lay inland around the place were intersected by frequent long, deep, and precipitous ravines, so that by this side also hostile approach had apparently been rendered impossible. Nevertheless, that one of the Northern generals to whom nothing ever seemed impossible, having cast the eye of desire upon this especial spot, now advanced upon it, and began operations in his silent, enduring, pertinacious way, which no men and no intrenchments could permanently withstand. His lieutenant, Sherman, made one desperate assault,--not, as it seemed, because there was a possibility of taking the place, but rather to demonstrate that it could not be taken. Then slower and more toilsome methods were tried. It was obvious that a siege must be resorted to; yet it was not easy to get near enough even to establish a siege.