Two images have been cleaned up, and aligned so that you can compare any portion in the zoom window.
Click the links above the viewport to toggle between them.
These photos found on the National Archives site contained significant damage to the negatives. One was posted reversed.
At first I thought they were from the same photo session, however, on closer inspection, it's obvious they are likely taken months apart. The 'earlier' photo shows a flood-swollen Tennessee River, mostly submerging Towhead Island. The Rolling Mill adjacent to the island is under construction by orders of Gen. Grant. By the time the 2nd photo was taken it had grown in size.