Auction description: Albumen CDV print mounted on brown paper (print 2.125 x 3.25 in.; style similar to the Albert Pike example offered as Lot 87).
Belle Boyd (1844-1900), dubbed the “Cleopatra of the Secession”, was known for seducing and/or eavesdropping on Union officers, then transmitting the intelligence to General Stonewall Jackson and others.
Source: Cowan’s auction item, sold for $228 in August 2014
Read about Belle Boyd from the Civil War Trust