After the Battle of Shiloh, Major General Henry W. Halleck, commander of Union forces in the West, was so upset at Grant’s performace and the awful casualties at Shiloh, assumed field command and put Major General George H. Thomas in command of Grant’s army. General Grant was made second-in-command overall, a vague position of no real authority.
Following the battle, the Confederate Army slowly retreated to Corinth, Mississippi, 22 miles south of Pittsburg Landing. General Halleck pursued cautiously, ordering elaborate entrenchments every night to protect his army slowing his advance. The result was what took a Confederate Army two days to travel prior to the Battle of Shiloh, took the Union Army six weeks.
The Union Army finally arrived at Corinth on May 28 and prepared for a bombardment of the city. However, General Beauregard, in command of Confederate forces, recognized that his army was vastly outnumbered ordered an elaborate deception plan to evacuate the city on May 29 and 30 thereby saving his Army. The deception was so effective the Union Army did not realize the Confederate Army was gone until they saw burning supplies abandoned by the Confederates.
When the advance on Corinth began, the Union Army had more than 150,000 men on the rolls, compared to the Confederate Army’s 70,000 men. However, by the end of May, the Union Army had only 95,000 effectives. More than half of the Union high command, including General Halleck, had dysentry.
The 1st OVI took an active part in the pursuit of the Confederates participating in a number of skirmishes with the enemy. After the occupation of Corinth on May 31st, the 1st OVI remained there on guard duty until June 10th, when they received marching orders to proceed to Chattanooga, Tennessee.