The soldiers, dressed in ragged blue uniforms, screamed "Aghhh!" and advanced, holding out long rifles with nasty-looking bayonets attached.
"Uh, that's close enough," one spectator said, getting a laugh from the crowd.
The soldiers were members of the 10th Illinois Volunteer Infantry, and they were demonstrating the basics of Civil War-era combat during a living-history event Sunday at the Graue Mill and Museum in Oak Brook.
In addition to the combat demonstrations, the members of the infantry set up exhibits to show what 19th-century weaponry and medicine were like.
The infantry also set up tents and cooking fires on the Graue Mill grounds in preparation for the solders' overnight camp-out.
Fred Mitchell of Oswego was one of Sunday's "soldiers." He said he got the Civil War bug from his father, who used to participate in "skirmishes" -- shooting competitions that use Civil War-era firearms.
"It's fun to relive history," Mitchell said. "I really like it when the young kids come by, because they usually don't know much about the Civil War at all. Seeing us in our uniforms, firing the weapons -- I think it makes an impression on them."
Janet Perlman of Wheaton attended Sunday's event with her 12-year-old son, Craig, who inspected the Civil War medical table stacked with vials of Black Tea and Tincture of Iodine.
"Learning about the war this way makes it come alive more," she said. "The visuals really stick with you."
The 10th Illinois Volunteer Infantry, a living-history re-enactment group, draws heavily from the Chicago area, as well as other parts of the state. The group is named after a real unit that fought for the Union Army from 1861 to 1865.