South Mountain State Battlefield seeks to preserve and interpret the first major Civil War battle to take place in Maryland. Fought on September 14, 1862, the Battle of South Mountain was a critical turning point in the American Civil War. The Union victories at South Mountain and Antietam (fought three days later) led President Abraham Lincoln to issue the Emancipation Proclamation. The state battlefield, located along the gaps of South Mountain, includes valuable farm and forestland, and is home to diverse wildlife. Only here does the Appalachian National Scenic Trail intersect a major Civil War battlefield. (source)
To learn about the Battle of South Mountain, visit the park's website.