(2007) Battery B, 4th U.S. Across Hagerstown Turnpike from near the southwest corner of the Miller cornfield. Bugler John Cook, who enlisted at age 13, worked as a cannoneer and was awarded the Medal of Honor, one of the youngest recipients in history. General John Gibbon personally worked as a gunner and cannoneer

From the NPS Cornfield Trail:

Stop 7 - Battery B, 4th U.S.
Just across the road are two cannons representing Battery B, 4th U.S. Artillery. Battery B moved forward with the initial Union attack. As soon as the guns moved into this position, they came under intense fire from Stonewall Jackson's men. Although Battery B suffered nearly 50% casualties in the fighting, it's firepower, coupled with the musketry of Hooker's infantry, and the timely arrival of the 12th Corps, helped shatter Hood's counterattack