Black Legion (1937)

"Many of the details about the Legion portrayed in Black Legion, such as the initiation oath and the confessions in the trial scenes, were based on known facts about the actual organization, but because American libel laws had recently been broadened in scope by court rulings, Warner Bros. was forced to underplay some aspects of the group's political activities to avoid legal repercussion. Nevertheless, the Ku Klux Klan sued Warner Bros. for patent infringement for the film's use of a patented Klan insignia, a white cross on a red background with a black square..."

Humphrey Bogart as Frank Taylor
Dick Foran as Ed Jackson
Erin O'Brien-Moore as Ruth Taylor
Ann Sheridan as Betty Grogan
Helen Flint as Pearl Danvers
Joe Sawyer as Cliff Summers
Clifford Soubier as Mike Grogan
Alonzo Price as Alf Hargrave
Paul Harvey as Billings
Dickie Jones as Buddy Taylor
Samuel S. Hinds as Judge
Addison Richards as Prosecuting Attorney
Eddie Acuff as Metcalf
Dorothy Vaughan as Mrs. Grogan
John Litel as Tommy Smith
Henry Brandon as Joe Dombrowski
Charles Halton as Osgood
Pat C. Flick as Nick Strumpas
Francis Sayles as Charlie
Paul Stanton as Barham
Harry Hayden as Jones
Egon Brecher as Old Man Dombrowski

Black Legion screenshot

Black Legion screenshot