Mary Fields, also known as Stagecoach Mary and Black Mary, was the first African American woman to work in the US Postal Service.
 Mary Fields was born a slave in Hickman County, Tennessee, around 1832. After the end of the Civil War, she was emancipated and found employment as a chambermaid aboard the Robert E. Lee, a Mississippi River steamboat.

 Fields was fearless in behavior. She carried several firearms, most notably a .38 Smith & Wesson under her apron to protect herself and the correspondence of wolves, thieves, and bandits, driving along the route with horses and a mule named Moses. She never missed a day, and her reliability earned her the nickname "Stagecoach Mary" due to her preferred mode of transportation.

 Fields died in 1914 at Columbus Hospital in Great Falls, and her funeral was one of the biggest the city had ever seen.