In the film, all of the men working on the still with Williams were white. But in reality, it was five African-American men, all of whom testified against Williams at trial.
David Marshall Williams was convicted of killing a Deputy Sheriff, not a Federal Agent. Also, differing from the film's depiction, the murder was an ambush by Williams and his still workers as the police attempted to transport evidence from the crime scene.
The final James Stewart movie filmed in monochrome (black and white) until Otto Preminger's Anatomy of a Murder (1959).
James Stewart actively sought the lead role, despite being too old for it, because the film reflected his conservative views.
The second starring feature in which James Stewart portrays a real-life person, the first being Monty Stratton in The Stratton Story (1949).