Who did the spying during the civil war?

During the American Civil War, both the Union and Confederate sides employed spies to gather intelligence on enemy movements and strategies. Notable figures included Union spies like Elizabeth Van Lew, who operated in Richmond, and Allan Pinkerton, who led a detective agency that provided critical intelligence. The Confederacy also had its own network, with figures like Rose O'Neal Greenhow, who used her social connections to relay information to Confederate leaders. Spying played a crucial role in the war, influencing several key battles and strategies.