And here's what you see from the other direction:
You are viewing this west of my position, you are looking east with the remains of the East Woods beyond the Cornfield in the foreground. Imagine if several regiments of your enemy were hidden from your view if you were advancing in this direction. Or imagine if your regiment, in line of battle, was advancing in a line parallel to the fence, suddenly your left flank or center would disappear from view. My, how confusing. Even more so when men are trying in earnest to kill you.
This rock ledge served as an impromptu fortress three times during the course of the Cornfield fight. Initially, Union troops under Doubleday enfiladed elements Hood’s Division. In subsequent action, Confederates of the 46th North Carolina, commanded by E.D. Hall would enfilade Union troops advancing along the Hagerstown Pike. Due to its commanding position of this rock ledge, relative to the Hagerstown pike, it becomes immediately evident that any troops positioned behind this outcropping possess a field of fire encompassing the road and any troops unfortunate enough to be on it. Ezra Carman, Antietam historian and colonel of the 13th New Jersey led some of those unfortunates and recalled the scene thus; “The men were being shot by a foe they could not see, so perfectly did the ledge protect them”.
The "Disaster in the West Woods", the destruction of Sedgewick's Division in the West Woods by Confederates under Early was due in great part to the fortunate (for Early's men) placement of a ravine system behind the Dunker Church that runs through the West Woods. Good luck and these ravines would channel Early's men to advantageous positions on the flank and in the rear of Sedgewick's doomed division. What passes in reports and historic accounts as superb or lackluster generalship is often more the work of chance and terrain.
Deep down in one of the ravines travelled by Early's men. Seldom did visitors venture into this area. Now, however the area is accessible on the Park's new West Woods trail.
Your only concern is that little guidon snapping in the breeze.
and his 1,700-man division concealed from view just beyond the lip of the swale, which will rise up and destroy your regiment.