William Harper is not listed in the Memorial Roll for the 15th found in Lindsley's Military Annals of Tennessee.
But, this is said of the regiment at Shiloh, ". . . it was ordered to Bethel Station, and went into camp about two miles from Purdy, Tenn., where it remained until the 4th of April, when it was moved forward to take part in the battle of Shiloh, in which the regiment was fearfully punished by the loss of nearly two hundred killed and wounded."