Meanwhile General Grant, at breakfast at Savannah, nine miles below Pittsburg Landing by river, but six miles in an air-line, heard the firing. He at once sent an order to General Nelson to march his division up the river to opposite Pittsburg; and, not aware that General Buell had arrived the previous evening, sent a letter out to meet him, advising him of the order given to Nelson and explaining the reason for not waiting in person for his arrival. Steaming up the river, he stopped at Crump's Landing at eight o'clock and directed Lewis Wallace to hold his division in readiness to move. Arrived at Pittsburg Landing, Colonel Pride, of his staff, at once organized ammunition trains, which were busy all day supplying the troops at the front. The Twenty-third Missouri, just arrived by boat, he hurried out to reinforce Prentiss. The Fifteenth Iowa, just arrived, and the Sixteenth, sent by Prentiss to the landing for ammunition, he directed to form line, arrest the tide of stragglers from the front, and organize them to return. Riding to the front, he found General Sherman a little before ten o'clock in his hottest engagement, still holding the enemy at bay in front of his camp; told him that Wallace would come up from Crump's Landing; sent word to Wallace to move; to Nelson, to hasten his movements; returned to the landing, dispatched the two Iowa regiments to reinforce McClernand, and proceeded to visit the other divisions in the field. The loaded wagons of McDowell's brigade, hurrying to the rear along the Purdy road, interfered with the formation of Sherman's new line. Behr's battery, galloping to the position assigned to it--the centre of the line--added to the difficulty. This battery was hardly in position and under fire before Captain Behr was killed, and the men abandoned their guns, fleeing from the field with the caissons. The line so disordered and broken was hard pressed by the enemy, and Sherman selected another line of defence, to his left and rear, connecting with McClernand's right. McDowell, nearly cut off by the enemy's pressing through the gap left by Behr's men, brought the remaining gun of this battery from its position near the bridge, and by a rapid fire pressed back the advance. His regiments became separated while struggling through dense thickets to the new position. The Fortieth Illinois found itself marching by the flank, with a deep ravine along its left, and a confederate regiment marching in parallel course not far to its right. Thus cut off, the Fortieth formed with its rear to the ravine, with a desperate effort drove its dangerous companion out of the way, and, pushing through the timber, came into a valley in rear of McClernand.