The film was directed by William A. Wellman, and starring James Cagney, Jean Harlow, Edward Woods, Donald Cook and Joan Blondell.

The screenplay is based on an unpublished novel—Beer and Blood by two former newspapermen, John Bright and Kubec Glasmon—who had witnessed some of Al Capone's murderous gang rivalries in Chicago.

[7][8] In 1998, The Public Enemy was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".

As youngsters in 1900s Chicago, Irish-Americans Tom Powers and his lifelong friend Matt Doyle engage in petty theft, selling stolen items to "Putty Nose".

In 1920, with Prohibition about to go into effect, Paddy Ryan recruits Tom and Matt as beer "salesmen" (enforcers) in his bootlegging business.

[9][10] Bright and Glasmon based their novel on actual people, having witnessed some of Al Capone's murderous gang rivalries in Chicago.

Wellman, who had served in World War I, like the brother of the main character, told Warner: "I'll bring you the toughest, most violent picture you ever did see".

Another reason for the switch is that the sound technology used in The Public Enemy was superior to that used in earlier films, making it no longer imperative to have an actor in the lead role who had impeccable enunciation.

[citation needed] Louise Brooks was the original choice for Gwen Allen, a woman with self-confessed weakness for bad men.

[citation needed] Yet in spite of his genuine shock and pain, Cagney stayed in character and played out the rest of the scene.

[14][15] Some, such as film critic Ben Mankiewicz, have asserted that Mae Clarke's surprised and seemingly somewhat angry reaction to the grapefruit was genuine, as she had not been told to expect the unscripted action.

She said that her only genuine surprise came later, when she saw the grapefruit scene appear in the final film, as it had been her understanding that they were shooting it only as a joke to amuse the crew.

The film featured a prologue[6] "apprising the audience that the hoodlums and terrorists of the underworld must be exposed and the glamour ripped from them" and an epilogue "pointing the moral that civilization is on her knees and inquiring loudly as to what is to be done."

[20] Andre Sennwald, who reviewed the film for The New York Times on its April 1931 release, called it "just another gangster film at the Strand, weaker than most in its story, stronger than most in its acting, and, like most, maintaining a certain level of interest through the last burst of machine-gun fire"; Woods and Cagney give "remarkably lifelike portraits of young hoodlums" and "Beryl Mercer as Tom's mother, Robert Emmett O'Connor as a gang chief, and Donald Cook as Tom's brother, do splendidly.

"[2] Time magazine called The Public Enemy "well-told" and noted, "Unlike City Streets, this is not a Hugoesque fable of gangsters fighting among themselves, but a documentary drama of the bandit standing against society.

"[21] Variety called it "low-brow material given such workmanship as to make it high-brow" which attempts to "square everything [with] a foreword and postscript moralizing on the gangster as a menace to the public welfare.

In 1989, an animatronics version of a scene from The Public Enemy was incorporated into The Great Movie Ride at the Disney-MGM Studios theme park in Orlando, Florida.

In 1998, The Public Enemy was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".

[24] In the 90's and early 2000's wrestlers Rocco Rock and Johnny Grunge would used the title of the movie when they formed the tag team in places like WWE, WCW, and ECW and they would both be in the Hardcore Wrestling Hall of Fame.