Cecil B. DeMille's original script developed the story as a musical, but changed his mind when Yul Brynner, dissatisfied with the treatment of the material, threatened to back out of the film.
Cecil B. DeMille's prologue fails to mention the great irony of the Battle of New Orleans: by the time it was fought, a treaty to end the War of 1812 had already been signed in London. But word of the signing did not reach New Orleans until weeks later.
Anthony Quinn plays the role of Beluche in the 1938 movie. For this one, he is the director. In fact, it is the only instance in his film career of taking on that job.
The Buccaneer was Cecil B. DeMille's last film. He was seriously ailing, and had to turn over direction of the film to his son-in-law, Anthony Quinn. DeMille oversaw production of the film, and appears in the prologue, but was unsatisfied with Quinn's efforts as director, as well as the work of old friend Henry Wilcoxen as producer, and tried to change and improve the film during and after production. DeMille died in January, 1959, only a month after the film's release.
Facts were changed to protect 1950s sensitivities. Lafitte did have an affair with a Claybourne lady, but it was the Governor's wife, not his daughter.
There is no historical evidence to prove that Lafitte actually was present during the battle.
There was a "Dominic Yu" in Lafitte's band of pirates, but modern research suggests "Yu" was actually an alias for Alexandre Lafitte, Jean's older brother, from whom he learned the buccaneer's trade.