Each of the approximately 100,000 soldiers bivouacked in the fields and woodlots around Sharpsburg, Maryland and along Antietam Creek knew what the morrow would bring. With the Army of Northern Virginia and the Army of the Potomac having been in close contact the last few days and the sharp firefight that flared up on the evening of September 16, a full-scale battle was imminent. Some opposing soldiers bedded down for the night within shouting distance of one another.
The tension in the air was palpable on the evening of September 16. Local civilians huddled together for safety or fled their homes, placing their properties in the hands of fate. Soldiers turned their thoughts to home before a stray picket shot brought them back to tomorrow’s task. And both the United States and Confederate States collectively held their breath, waiting to learn the outcome of the campaign in Maryland, upon which hinged the survival of their nations. The stakes could not have been higher. Every soldier, from the lowest private to the highest general, knew the importance of the next day’s fight and knew the inevitability of its coming.
Burdened with these thoughts, sleep did not come easily to the soldiers in blue or gray that night. An overnight rain shower and sporadic picket firing made the task a near impossibility. Just a few days after the battle, one Confederate artillerist recorded his memory of the night of September 16, 1862:
The picket firing was maintained till nine o’clock, and indeed so often renewed during the night that it was difficult to sleep. It was now evident that the morrow would be a day of blood. As we lay down upon the field, and look up into the great sky, we could but blush for the wickedness of man. Oh, how calmly and reproachfully do the bright stars move on in their courses. It was a beautiful night; and no man who lay upon that field, and realize the deep tragedy which was to be enacted on the morrow, could be but sad and thoughtful. The past was present as well as the future, and we scanned the three together, and tried to learn wisdom from the study. We thought of dear ones far away, and were glad that they know not of the trying hour that the setting stars were bringing rapidly on. At three every man was at his post, and awaited in solemn silence the day-dawn. No sooner did the light break in the east, than the picket firing began, and increased in fury until about sunrise, when artillery and infantry together grapple in the terrible fight.
The sunrise on September 17, 1862 inaugurated the bloodiest single day in American history.