The Army of the Ohio Major General Don Carlos Buell

Soon after the consolidation of the Departments of the Ohio and Missouri, General Halleck ordered General Buell to move his army from Nashville to Savannah, Tenn., and form junction with the Army of the Tennessee. Upon General Buell's suggestion to march his army across the country rather than transfer it by boats, it was so ordered, and General Buell with the advance of his army reached Savannah Tenn., April 5, 1862. Early Sunday, April 6, General Grant informed General Buell by notea of the situation at Shiloh and ordered General Nelson to march his division up the east side of the Tennessee to a point opposite Pittsburg Landing, where boats would be found to ferry him across the river. General Buell and staff reached Pittsburg Landing by boat between 2 and 3 o'clock. Ammen's brigade, the advance of Nelson's division, arrived upon the field at about 5:30 p.m., a part of it engaging in the repulse of the Confederates in the last attack of Sunday. During the night the remainder of Nelson's division and Crittenden's division arrived on the field, and early Monday morning two brigades of McCook's division reached the Landing. In action of the 7th the Army of the Ohio occupied the left of the Union line, extending in a semicircle from the Tennessee River, south of Dill Branch, to north side of the Corinth road 1 mile form the Landing, Nelson's division on the left, Crittenden in the center, McCook on the right. "The enemy on a line slightly oblique to ours and beyond open fields with a battery in front of Nelson's left, a battery in front of Crittenden's left, a battery in front of Crittenden's right and McCook's left and another battery in front of McCook's right. A short distance in rear of the enemy's left were the encampments of McClernand's and Sherman's divisions, which the enemy held. While troops were getting into position, Mendenhall's battery engaged the enemy's second battery with some effect. Bartlett's battery engaged the enemy's third battery. The divisions of the Army of the Ohio moved forward preserving their relative positions in line and became engaged about 8 a.m. They advanced slowly until about 2 p.m., when Wood's division arrived just as the final retreat of the Confederates began. In the forward movement McCook's division kept the main Corinth road, Crittenden's division about the directions so that at about 11 a.m. Veatch and Tuttle, from the Army of the Tennessee, were moved into the interval between McCook and Crittenden and became engaged in the Review field. At 4 p.m. the Confederates had retired from the field, and the Army of the Ohio bivouacked on a line extending from Stuart's camps through Prentiss's camps to near Shiloh Church. Terrill's battery (H), Fifth United States, belonging to McCook's division, was detached for service with Nelson and was in action on Hamburg road and at the Peach Orchard.

Second Division - Brigadier General Alexander M. McCook

Fourth Division - Brigadier General William Nelson

Fifth Division - Brigadier General Thomas L. Crittenden

Sixth Division - Brigadier General Thomas J. Wood