Battle of Antietam, Maryland - Dawn approached slowly through the fog on September 17, 1862. As soldiers tried to wipe away the dampness, cannons began to roar and sheets of flame burst forth from hundreds of rifles, opening a twelve hour battle that swept across the rolling farm fields in western Maryland. This clash between North and South changed the course of the Civil War, helped free over four million Americans, devastated Sharpsburg, and still ranks as the bloodiest one-day battle in American History.