 William Terrill served as assistant inspector general in Washington, D.C., and then commanded a battery of artillery in the Army of the Ohio at the Battle of Shiloh.On September 9, 1862 he was promoted to brigadier general of volunteers and took command of the 33rd Brigade in the Army of the Ohio.Terrill was not popular with all of the men in his brigade due to his Virginia background and for being a strict disciplinarian.