Book excerpt: Approximately 110,000 soldiers of the Union and Confederate armies fought along the banks of Antietam Creek in the bloodiest single-day battle in American history. In 12 hours of fighting, approximately 23,000 men fell, either killed, wounded, or missing, forever scarring the landscape around the town of Sharpsburg. Established as the Antietam Battlefield Site in 1890, Antietam National Battlefield became a National Park Service landmark in 1933. The park grew from 33 acres in the 1890s to encompassing over 3,000 acres today. Some of the Civil War's most recognizable landmarks now sit within its boundaries, including Dunker Church, Bloody Lane, and Burnside Bridge. The events that occurred across the fields and woodlots around Sharpsburg and along Antietam Creek bring hundreds of thousands of visitors to Antietam National Battlefield every year. ?Kevin Pawlak serves as a certified battlefield guide at Antietam National Battlefield. Antietam National Battlefield is filled with historic photographs of the battlefield and its development from the collections of Antietam National Battlefield Library, the Library of Congress, the New York Public Library, the United States Army Heritage and Education Center, private collections, and more.