Lot 4182, No. 200:   Sailors and a cannon on deck of a gunboat, between 1861-65.   Photograph print from stereo card.  Courtesy of the Library of Congress.  (4/23/2015).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/127906254@N06">National Museum of the U.S. Navy</a>
<p><a rel="nofollow" class="external text" href="https://www.flickr.com/photos/127906254@N06/17289555901/">1s02819u</a>
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Alternative source: <a rel="nofollow" class="external free" href="https://www.loc.gov/item/2011660490/">https://www.loc.gov/item/2011660490/</a>