Allan Pinkerton and J. Edgar Hoover both played significant roles in shaping law enforcement in the United States, emphasizing the importance of intelligence gathering and surveillance. Pinkerton founded the Pinkerton National Detective Agency, pioneering private detective work and employing innovative investigative techniques. Similarly, Hoover, as the first director of the FBI, expanded federal law enforcement and utilized modern technology for crime-fighting, often prioritizing national security. Both figures have been criticized for their controversial methods, which sometimes blurred the lines between legal authority and personal or political agendas.