During the weeks before the Battle of Shiloh, the 18th Louisiana was one of the regiments called to the tiny crossroads town of Corinth, Mississippi, for Confederate General Albert Sidney Johnston's planned attack on Union forces encamped near Pittsburg Landing, Tennessee. At Shiloh, the 18th Louisiana was organized into Col. Preston Pond's brigade. It was while serving in this brigade that the regiment and their commander received their baptism by fire. Pond's brigade attacked the Federal right, against the divisions of Union generals William Tecumseh Sherman and John A. McClernand. During one of these attacks, Colonel Mouton was wounded. After this Confederate defeat in April 1862, General P.G.T. Beauregard ordered a withdrawal back to Corinth. After arriving there, the 18th Louisiana was sent back to Louisiana to replenish its depleted ranks.