This is the classic view of Dunker Church, which was at about Ground Zero for the Battle of Antietam. During much of the fighting Confederates held this position as they fought Federals advancing from camera right. This particular area was basically an artillery park for caissons and horses, while the Confederate guns were actually farther off camera to the right. Eventually, after brutal fighting seldom seen in the Civil War or elsewhere, Union troops fought their way into this area.
The dead in the Park picture are Confederates, possibly cannoneers, but more likely Confederate infantry, which counterattacked in this area. These pictures, and many more, are discussed in the tour guide, Showdown at Antietam, discussed elsewhere on this site.