That Field of Blood: The Battle of Antietam, September 17, 1862

September 17, 1862—one of the most consequential days in the history of the United States—was a moment in time when the future of the country could have veered in two starkly different directions.

Confederates under General Robert E. Lee had embarked upon an invasion of Maryland, threatening to achieve a victory on Union soil that could potentially end the Civil War in Southern Independence. Lee’s opponent, Major General George McClellan, led the Army of the Potomac to stop Lee’s campaign. I...