There are several walks at the Antietam. Before you start walking I highly recommend that you check the visitor center for the guided ranger tours.
This battle was one of the first in history that was extensively photographed. I've included a few in the slide show (National Park Site that details Historic Photographs by Alexander Gardner).
The walk that I detailed includes the Mumma Farm, the Cornfield and Bloody Lane. The battle took place on a broad front. A major portion of the battle was covered by this walk. The other area (a short drive away) took place at the Burnside Bridge.
Links of interest:
- Antietam National Battle Field Park
- Antietam NP - Hiking the Battlefield
- Antietam NP - Bloody Lane Trail Map
- Antietam NP - Historic Photographs by Alexander Gardner
- Wikipedia - Battle of Antietam
- Wikipedia - Antietam Battlefied Park
- National Park Service - Soldiers and Sailors Database
- Book: Antietam: Antietam National Battlefield, Maryland (1994)
- Civil War Trust - Antietam
- Civil War Traveller Guide - Antietam
- US Army - Staff Ride - Antietam