I don't think the photo was taken for a newspaper. More likely it was taken as part of a set of stereoscopic images that could then be sold by photographers, department stores, newspaper ads, etc. The 1870 may reflect the date the set was copyrighted/published and then sold to the merchants, or whoever, who then sold the sets to the public.
Here's a link to a collection from the Library of Congress that has mostly stereoscopic images that date to the Civil War:
https://www.loc.gov/pictures/search/?q=r...st=gallery
Here's a 1902 copyright dated stereoscopic image of President William McKinley and Booker T. Washington, which obviously can't be the date of the image:
I checked and this image was taken on 16 Dec. 1898 when Pres. McKinley visited the Tuskegee Institute.