In the film, John Patterson (Richard Kiley) is depicted as supportive of African-American Zeke Ward (James Edwards) and his family. In real life, following his term as Alabama attorney general (1954-1958), he ran for governor in 1958, ran an openly racist campaign and won. One of his opponents, George Wallace, had run as a racial moderate and told his friends after the election, "John Patterson out-niggered me, and I'm never gonna be out-niggered again." Four years later, in 1962, Wallace won the governorship of Alabama as an avowed segregationist.
Such was director Phil Karlson's attention to detail, he had some of his actors wear the actual clothes of their screen counterparts.
The film was in production so quickly, some of the criminals it was portraying were standing trial while filming was taking place.
This is one of Martin Scorsese's personal favorite films.