In my Civil War short, In the Shadows, I briefly mention Allan Pinkerton and use he and his agency as the basis for Marion’s foray into spying. Actually, it was Allan’s co-worker, possible lover, Kate Warne that gave me the idea. She was a woman who did as she pleased, and working as a Pinkerton was what she wanted to do. None of this secretary business. No, Kate wanted to be a spy. Not being a stupid man, Allan agreed to a trial case. She didn’t fail, and went on to save President Lincoln before his inauguration.
President Lincoln hired the Pinkerton Detective Agency, during the Civil War, to organize a “secret service” to obtain military information on the Confederates and sometimes act as Lincoln’s bodyguard. Allan traveled under the name Major E.J. Allen. After the war, the agency was often hired by the government to perform many of the same duties that are now part of the Secret Service, the FBI, and the CIA’s duties.