Then came Grant. His coming opened a new chapter in the war for the possession of the Mississippi river. He brought to bear upon the problem all that superb determination, that dauntless courage and that splendid obstinacy which afterward won for him his place in history. He had no particular plan at first, because he was not yet familiar with the terms and conditions of the problem he was set to solve. But he intended to take Vicksburg, and he did not intend to fritter away the energies of his army in little side expeditions which in no important way could affect the general result. He called in all the troops who had been sent by McClernand to unimportant points and set himself at work to find a way of conquering the stronghold, the conquest of which was the sole object of his campaign. The difficulties that presented themselves were many and exceedingly great. While Vicksburg, itself, was perched upon high hills, every conceivable road to it lay through swamps and morasses naturally defended by streams that were bottomed with unfathomable mud. The best approaches to the town were from points farther down the river, but except by desperate endeavor it was impossible to reach those approaches so long as the works at Vicksburg completely commanded the stream. Grant was satisfied that if he could reach any point on the river below Vicksburg where a landing was practicable he could march thence into the rear of the town and compel its surrender. In order to accomplish this he sent McClernand and Sherman to cut a canal across the peninsula made by the great bend in the river west of Vicksburg. This effort proved a failure, partly through engineering difficulties and partly because there were bluffs on the eastern side of the river below Vicksburg, which the Confederates promptly fortified and armed in such fashion as to command the outlet of the proposed canal. Grant soon saw that even if he should succeed in making this canal cut-off, he must still find himself confronted on the river bank by heavily armed and high-placed works as difficult for his flotillas to pass as were the bluffs at Vicksburg itself. He continued the work, however, in despair of anything better to do until early in March when a sudden flood in the Mississippi completely overflowed the peninsula on which the Federals were working, and compelled Sherman to withdraw hastily to save his army from drowning. Grant's next scheme was by cutting another canal to carry his flotilla through Lake Providence west of the Mississippi, and thence by way of the many navigable bayous in that quarter to a point on the river well below Vicksburg. A good deal of digging was done in an attempt to carry out this plan, but in the end it failed as completely as the former one had done.