Bass Reeves was a runaway slave, gunfighter, farmer, scout, tracker, railroad Agent and deputy U.S. Marshal. He spoke and understood the Five Civilized Tribal languages including Cherokee, Choctaw, Chickasaw, Seminole and Creek. Bass was one of the first African-American Deputy U.S. Marshals west of the Mississippi River, mostly working in the deadly Indian Territory. The region was saturated with horse thieves, cattle rustlers, gunslingers, bandits, bootleggers, swindlers, and murderers. Reeves made more than 3,000 to 4,000 arrests in his lifetime, only killing twenty men in the line of duty.

The United States Marshals Service (USMS) is a federal law enforcement agency in the United States. The Marshals Service serves as the enforcement and security arm of the U.S. federal judiciary, although it is an agency of the U.S. Department of Justice and operates under the direction of the U.S. Attorney General. It is the oldest U.S. federal law enforcement agency, created by the Judiciary Act of 1789 during the presidency of George Washington as the "Office of the United States Marshal". The USMS as it stands today was established in 1969 to provide guidance and assistance to U.S. Marshals throughout the federal judicial districts.