Final answer:
The Pinkerton Detectives were a private detective agency known for their investigative work and collaboration with law enforcement agencies in the United States.
Step-by-step explanation:
The Pinkerton Detectives were a private detective agency founded by Allan Pinkerton in the United States in the mid-19th century. They were known for their investigative work in solving crimes, protecting businesses, and working closely with law enforcement agencies. The Pinkerton Detectives were often hired by businesses and government agencies to handle cases that required specialized knowledge and skills. They played a significant role in the development and professionalization of detective work in the United States.