Depiction of the ironclads USS Monitor and USS Galena bombarding Confederate forces as Union General McClellan's army withdraws following the Battle of Malvern Hill, 2 July 1862.
The other two ships visible are probably USS Aroostook (beyond Monitor's bow) and USS Jacob Bell (behind Monitor, at left).
United States Navy Gunboats Covering The Retreat at Malvern Hill Virginia
Engraving after a drawing by C. Parsons, published by Virtue, Yorston & Company, New York, circa the later 19th Century.
Northern Naval Superiority and the Economics of the American Civil War
Author David Surdam has finally done what others should have done years ago: he has connected the dots between the detailed studies of blockade running, weapons production, materials production, rail transport, and naval strategy to produce a definitive analysis of the blockade's effectiveness.