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The most important of the battles between the western armies during the Civil War, resulting in frightful loss of life on both sides. This fight lasted two days, April 6 and 7, 1862, the Confederates being forced to retreat on the afternoon of the second day. Grant commanded the Federals, numbering 40,000, and expected 7000 more under Buell to join him. His line extended two miles along Lick Creek, Prentiss holding the left, McClernand the centre and William T. Sherman the right. The Confederates, 45,000 strong, were led by Albert Sidney Johnston with Beauregard, Bragg and Hardee as his chief lieutenants. Johnston, confident of success, began the attack by falling heavily upon Sherman's and McClernand's divisions. These generals gave way, but the Confederates sustained great losses. In the afternoon Johnston was shot and Beauregard assumed command of the Confederates. An opening in Prentiss' ranks enabled the Confederates to gain a considerable advantage the first day. The next morning Grant, now joined by Buell, assumed the offensive. Throughout the day the advantage lay with the Federals. A charge led by Grant himself in the afternoon began the rout, but the roads were too rough to permit of pursuit. The Federal losses were about 13,500, the Confederate about 14,000.