Allan Pinkerton affiliated with the notorious Banditti of the Prairie. After observing their movements for some time he informed the local sheriff, who arrested them. This later led to Pinkerton being appointed, in 1849, as the first police detective in Chicago, Cook County, Illinois. In 1850, he partnered with Chicago attorney Edward Rucker in forming the North-Western Police Agency, which later became Pinkerton & Co, and finally Pinkerton National Detective Agency, still in existence today as Pinkerton Consulting and Investigations, a subsidiary of Securitas AB. Pinkerton's business insignia was a wide open eye with the caption "We never sleep." As the US
Baldwin–Felts Detective Agency agent, a position he held until his retirement, in 1930. Thomas Lafayette Felts was a native of Galax, Virginia, who was educated as a lawyer and was a member of the Virginia Bar Association. In 1900, he joined the Baldwin Detective Agency as a partner who could provide legal advice to the firm. In 1910, the name of the agency was changed to the Baldwin–Felts Detective Agency, and its headquarters were in Bluefield, West Virginia. Originally, the company provided investigative services to railroads for train robberies and other crimes. Little is known about this chapter in the history of Baldwin–Felts,