Which year marked the introduction of a formal detective agency in Boston?

The year 1846 is significant as it marks the establishment of the first formal detective agency in Boston, which was crucial in the evolution of criminal investigation practices in the United States. This agency was created in response to growing urban crime and the need for a more organized approach to law enforcement and investigation. The establishment of such agencies laid the groundwork for modern detective work, introducing methods of surveillance, information gathering, and investigation techniques that would come to be essential in law enforcement.

The other years listed did not coincide with the establishment of a formal detective agency in the city. While law enforcement and investigative practices were certainly evolving during this period, 1846 specifically stands out as a pivotal moment in the history of criminal investigation within Boston.