On Thursday, June 18, 1863 at Vicksburg Ulysses Grant removed General John McClernand from command of the Union’s Thirteenth Army Corps. At Champion’s Hill in late May 1863, McClernand had not followed Grant’s orders to attack with his entire corps.
After the battle, Grant deemed McClernand’s report on the battle to be “inaccurate” as well as “pretentious and egotistical.” After futilely assaulting Vicksburg’s defenses in late May, McClernand then issued a congratulatory order to his troops, praising his corps while casting aspersions on both Sherman’s and McPherson’s troops.
This short sighted act violated both the War Department’s and Grant’s standing orders. Grant replaced McClernand, who he believed both insubordinate and incompetent, with General Edward O.C. Ord, an officer who would serve Grant loyally throughout the rest of the Civil War.