Alan Pinkerton, who after the war formed his famous detective agency.

Jay R. Bonansinga has written:

'Oblivion'

'The sinking of the Eastland' -- subject(s): Eastland (Ship), Shipwrecks

'Pinkerton's war' -- subject(s): Detectives, Private investigators, Secret service, History, Biography, Pinkerton's National Detective Agency

'Bloodhound'

'The sleep police' -- subject(s): Serial murders, Fiction

'Sick'

'The Black Mariah'

Never made by S&W and never used by the Secret Service.

Probably because Pinkerton had experience in policing and detective work.

Pinkerton was the first police detective in Chicago, Cook County, Illinois. In 1850, formed the North-Western Police Agency, which later became Pinkerton & Co, and finally Pinkerton National Detective Agency. Pinkerton's agency solved a series of train robberies during the 1850s, and was through these that Pinkerton came into contact with George McClellan, who was the Chief Engineer and Vice President of the Illinois Central Railroad.

Walter S. Bowen has written:

'The United States Secret Service' -- subject(s): United States, United States. Secret Service