He read a slave's account of the war years, in which the man noted: "It seemed like your children belonged to everyone but you."
Bardaglio spoke Saturday afternoon at the Tatem Arts Center at Hood College. February is national Black History Month.
Bardaglio's appearance was part of a monthlong speakers' circuit sponsored by the Maryland Humanities Council.
Bardaglio said that for many of the children who lived through - and even fought in - the Civil War, making sense of the conflict took the rest of their lives.
Kids were forced to endure the same circumstances as adults, from taking top roles in the military to enduring gruesome scenes such as seeing piles of dismembered body parts.
"Not the thing I would like my 13-year-old doing," Bardaglio said.
Bardaglio said children who were not in the Civil War were still passively experiencing the conflict through letters from their fathers at the battle lines.
Bardaglio said most children entered the military ranks as drummer boys.
Because the kids were considered "non-combatants," they were allowed onto battlegrounds without concern for their age, he said. Bardaglio said some children became soldiers at ages as young as 12.
Bardaglio told the story of a boy who traded a musket for his drum after a piece of shrapnel ricocheted off a tree and poked a hole in his instrument. The boy later became a sergeant at age 13, Bardaglio said.
Kids were given uniforms that were sometimes several sizes too large, and they were harassed about their size in army camps, Bardaglio said. "Sometimes, more than words were exchanged," Bardaglio said.
While it made them "serious beyond their years," many of the kids adapted to army life quickly, and began to understand the concepts of battle and grow accustomed to seeing their comrades killed, Bardaglio said.
Bardiglio said no one has ever studied the impact of the war on children.