The annual Memorial Illumination is "held the first Saturday in December because it provides a maximum amount of darkness and the battlefield leases about half the park to local farmers. The later start gives them time to clear their crops."
Nearly 23,000 luminaries are placed to honor each soldier killed, wounded or missing during the Battle of Antietam on Sept. 17, 1862.
"It's a tangible way to see 23,000," said Keith Snyder, chief of resource education and visitor services for the battlefield. "This was the bloodiest day in American military history. It's four times D-Day,