Original: The Battle of Antietam (also known as the Battle of Sharpsburg, particularly in the South), fought on September 17, 1862, near Sharpsburg, Maryland, and Antietam Creek, as part of the Maryland Campaign, was the first major battle in the American Civil War to take place on Northern soil.
Simplified: The Battle of Antietam (also known as the Battle of Sharpsburg, particularly in the South) was a battle fought on September 17, 1862.