This Week on History Happy Hour: Civil War historian Scott Hartwig has been researching the Battle of Antietam for decades. Now he has written a definitive hour-by-hour tactical history of the battle, I Dread the Thought of the Place: The Battle of Antietam and the End of the Maryland Campaign. The memory of the Battle of Antietam was so haunting that when, nine months later, Major Rufus Dawes learned another Antietam battle might be on the horizon, he wrote, "I hope not, I dread the thought of the place."

Join us as Scott takes a deep dive into the bloodiest day in American military history.

D. Scott Hartwig served in the National Park Service for 34 years as an interpretive ranger and was a supervisory historian, including 20 years at Gettysburg National Military Park. He has authored numerous articles, essays and books on Civil War subjects and has often talked about Civil War topics – including the Battles of Gettysburg and Antietam – on the History Channel and Discovery Channel. He was the author of a noted work on the latter, entitled To Antietam Creek: The Maryland Campaign from September 3 to September 16. His recent book, I Dread the Thought of the Place, received an Honorable Mention for the American Battlefield Trust Prize for History.