Alexander Hall was the original director, but fell ill with pleurisy and was replaced by Rowland V. Lee after two-thirds of the film was shot. The length of principal photography suggests that Lee reshot or expanded most of Hall's material, resulting in many cast changes. It is not known how much of Hall's footage remains in the film.

Both Fisk and his partner Ned Stokes (called Nick Boyd in the movie) were married but competed for the affections of showgirl Josie Mansfield. In real life she was a world-wise dark-haired, full-figured woman who bore little resemblance to the innocent, apple-cheeked blonde sincerity of Francis Farmer. Stokes and Mansfield blackmailed Fisk, and Stokes shot Fisk to death in 1872. Although the dying Fisk named Stokes as his murderer, he only served four years of a six year term for manslaughter.

Many of the original cast in studio records and casting call lists were not seen in the film. These include (with their character names): George Lollier (Reporter), 'Frank Marlowe' (Reporter), Jack Carson (Reporter), Eddie Hart (Reporter), Max Wagner (Reporter), Frank M. Thomas (Lawyer), Oscar Apfel (Wallack), George Offerman Jr. (Usher), Sidney Bracey (Waiter), Don Brodie, Lloyd Ingraham (Man in New York Restaurant), Frank Mills (First Mug), Russ Powell (Second Mug), Ethan Laidlaw (Third Mug), Edward LeSaint (Member of the Board of Directors), Edward Peil Sr. (First Gentleman), Tom Ricketts (Member of the Board of Directors) and William Worthington (Judge). Henry Kolker was listed in the cast by a n

No mention is made of Jay Gould, the notorious robber baron, who conspired with Fisk to corner the gold market in The Panic 1869, three years before Fisk's death.

The Bowery Boys employed by Vanderbilt against Fisk have no relation to the long-running series of the same name but were a real-life Manhattan gang later portrayed in more detail in Martin Scorsese's "Gangs of New York."

The film lost $530,000 at the box office, RKO's biggest failure in 1937.

The only military experience that Fisk ever had was during the National Guard intervention during New York's Orange Riots in 1870 between Irish Catholics and Protestants.

Unlike the events in the film, Jim Fisk was shot and killed in a fight over a woman. Josie Mansfield was only one of his romantic interests.