This image from a West Point atlas has been rotated so north is at the top, and TwoScarsUp has added more labels to make it easier to read. (Note that the "North arrow" is not perfectly straight "up"—this is correct.) The map shows the positions of the Union and Confederate armies on the Shiloh battlefield at the end of the second day of fighting on April 7, 1862.  West Point's positioning of the Union troops agrees with O. Edward Cunningham's "Shiloh and the Western Campaign of 1862" map on page 366.
United States Military Academy (a.k.a. West Point), Department of Military Art and Engineering, with Colonel Vincent J. Esposito as the chief editor. Additional labels added by TwoScarsUp.
This is a modified and cropped file from page (image 46) of the West Point Atlas of American Wars Volume I, which can be found in the Library of Congress <a rel="nofollow" class="external text" href="https://www.loc.gov/item/59007452/">here</a>.