The situation was this: The enemy had about sixty thousand men at Vicksburg, Haines' Bluff, and at Jackson, Mississippi, about fifty miles east of Vicksburg. Grant, when he started, had about thirty-three thousand men. It was absolutely necessary for success that Grant, with inferior numbers, should succeed in. destroying the smaller forces to the eastward, and thus prevent their union with Pemberton and the main army at Vicksburg. His plan, in brief; was to fight and defeat a superior enemy separately and in detail. He lost no time in putting his plan into action, and pressing forward quickly, met a detachment of the enemy at Port Gibson and defeated them. Thence he marched to Grand Gulf, on the Mississippi, which he took, and which he had planned to make a base of supply. When he reached Grand Gulf, however, he found that he would be obliged to wait a month, in order to obtain the reinforcements which he expected from General Banks at Port Hudson. He, therefore, gave up the idea of making Grand Gulf a base, and Sherman having now joined him with his corps, Grant struck at once into the interior. He took nothing with him except ammunition, and his army was in the lightest marching order. This enabled him to move with great rapidity, but deprived him of his wagon trains, and of all munitions of war except cartridges. Everything, however, in this campaign, depended on quickness, and Grant's decision, as well as all his movements, marked the genius of the great soldier, which consists very largely in knowing just when to abandon the accepted military axioms.