Final answer:
The U.S. Marshal's Service, established in 1789, is the oldest policing authority in the United States, predating all other federal and many local law enforcement agencies.
Step-by-step explanation:
The oldest policing authority in the United States is the U.S. Marshal's Service. Established in 1789, the U.S. Marshal's Service is the federal law enforcement agency that predates all other federal law enforcement agencies, including the FBI. Unlike the FBI which deals with more complex and resource-intensive criminal investigations, the U.S. Marshals primarily focus on fugitive operations, transporting prisoners, protecting witnesses, and managing assets seized from criminal enterprises.
Local sheriff's offices date back to colonial times, but their formation varied from one location to another. While the sheriff's office is one of the oldest law enforcement entities, it is not a single national body. Municipal police agencies and the FBI (Federal Bureau of Investigations) were established later. The FBI, founded in 1908, is a nationwide federal investigative body that tackles federal crimes, which contrasts with the often broader jurisdiction and responsibilities of local and state police officers.