Looking north up the Antietam Creek from the Burnside Bridge. The steep banks on the left are those the Union soldiers
would have had to climb if they had tried to ford the creek instead of crossing the bridge.
Antietam National Battlefield, Sharpsburg, Maryland.

 

Looking north up the Antietam Creek from about the same location as the image above, September 1862.
Courtesy of the Library of Congress.
Sharpsburg, Maryland.