One of Rousseau’s men, John M. Kumler, described the action at Shiloh soon after the battle.
"Camp before Corinth, Mississippi, May 19, 1862, to his cousin Kate. “I have no doubt that you are a little anxious about the results of the bottle, but the reports were considerably exaggerated I admit. But the loss was great, but Johnnie, white headed Johnnie, came out of the fiery ordeal without a scratch. I imagine I saw you looking over the list of wounded and dead to see if you recognize the name of some friend, a relative or perhaps a lover. Well after such a battle one is entirely justifiable in exercising so great interest in behalf of wounded soldiers. It has robbed many mother of her husband, cut short the bright career of many a brave youth, and has sent a pang to the hearts of swains after hearing that their lovers fell victims to death on the fatal field of Shiloh. April 6-7 are days long to be remembered by the surviving patriot soldiers. Many rebels received their rewards on those fatal days. You ask whether I killed any secesh, whether I saw any fall I aimed at. Now these are questions I cannot answer. 1st you may think it very strange but I didn’t see anyone to shoot at because the underbrush was so thick we couldn’t see much more than 50 yards. We fought all day behind trees if they were handy and when they were not lay down to fire and load, which saved many an inspiring youth. As a general thing they shot too high but I tell you the balls discoursed some soul stirring music over our heads, and had it not been for a generous old tree that had fallen I too would no doubt have been obliged to bite the dust. But we drove the rascals from every position they took, capturing a battery. I don’t know then whether I killed any, but I, like the rest, shot directly where I saw the smoke of a gun. And I shot at the colors once or twice. It was a serious time, I assure you. It was affecting to look around to see the wild desolation of the previous day. It was truly a trial for energy but I was confident that I was engaged in a just cause and fearless since I was sure that I was fighting the enemies of my country, of the cherished principles of freedom. You ask how I kept from fainting on the day of the battle. Now you know there is a good deal in getting used to a thing. Before I was in the mess one hour I feared nothing, was calm and composed, loaded with alacrity, shot with as much precision as possible…I shot at the sesesh like an old hand at the bellows, but I don’t know whether the rebel digestive apparatus suffered in consequence or not – but I rather think it did… Now there is no telling how soon we will fight again. We have been under marching orders for some days, to be ready to march at a moments notice, and by the time this reaches you tis hard to tell what will turn up…Don’t be scared Kate because I am not in a dangerous condition at all.”
It is signed John M. Kumler, Co. D, 15th U.S. Infantry.