"Battle of Antietam" by Thure de Thulstrup, circa 1887. (Thure de Thulstrup/LIBRARY OF CONGRESS PRINTS AND PHOTOGRAPHS DIVISION)

The National Park Service will announce a multi-state commemoration of the Maryland Campaign of the Civil War that culminated with the single highest-casualty day in the conflict at the Battle of Antietam, also known as Sharpsburg. The announcement is scheduled for mid-morning today at the Lincoln Memorial.

According to a press release, national battlefield parks in Maryland, Virginia and West Virginia will participate in a series of events beginning July 13, leading up to the 150th anniversary date of Antietam on Sept. 17.

In the summer of 1862, Gen. Robert E. Lee led his troops from Virginia across the Potomac River into Maryland, with the intention of forcing a showdown with Gen. George B. McClellan’s Army of the Potomac. Part of that action included Harper’s Ferry in what is now West Virginia.

Events are to include guided tours of the battlefields, living history demonstrations and commemorative programs.