Civil War Espionage and Secret Services

Neither side entered the Civil War with a permanent modern intelligence service. Military commanders, politicians, detectives, scouts and civilians therefore created overlapping networks to gather information, intercept messages and identify suspected agents.

Allan Pinkerton organised intelligence for George B. McClellan, while Lafayette C. Baker later directed federal detective and counterintelligence operations. Confederate agents used sympathisers, couriers and networks in Washington, Richmond and border states.

This context supports fiction about spies, actors, detectives, military prisons and romantic relationships complicated by loyalty, secrecy and the absence of clear rules for intelligence work.