13 inch mortar "Dictator" in front of Petersburg, Virginia

Photograph shows Union officers and enlisted men standing around a large mortar on a platform on a flatbed railroad car near Petersburg, Virginia.
No. 4794.

Handwritten on back of mount: Gardner's photographic sketch book of the war. Washington, DC: c1866, vol. 2, plate 75, E468.7 .G2 (Case Y) Copy 1.
Forms part of: Civil War Photographs (Anthony-Taylor-Rand-Ordway-Eton collection).
Handwritten on back of mount: Miller, vol. III, p. 186.
Published in: The tradition of technology : Landmarks of Western technology ... / Leonard C. Bruno. Washington, D.C. : Library of Congress, 1995, p. 249.
Exhibited: "The Civil War in America" at the Library of Congress, Washington, D.C., 2012-2013.