On this morning 150 years ago, Union and Confederate troops clashed at the crossroads town of Sharpsburg, Md. The Battle of Antietam remains the bloodiest single day in American history.
The battle left 23,000 men killed or wounded in the fields, woods and dirt roads, and it changed the course of the Civil War.
It is called simply the Cornfield, and it was here, in the first light of dawn that Union troops — more than 1,000 — crept toward the Confederate lines. The stalks were at head level and shielded their movements.