To play Rocky, James Cagney drew on his memories of growing up in New York's Yorkville, a tough ethnic neighborhood on the upper east side, just south of Spanish Harlem.. His main inspiration was a drug-addicted pimp who stood on a street corner all day hitching his trousers, twitching his neck, and repeating, "Whadda ya hear! Whadda ya say!" Those mannerisms came back to haunt Cagney. He later wrote in his autobiography, "I did those gestures maybe six times in the picture. That was over thirty years ago - and the impressionists have been doing me doing him ever since."
The Dead End Kids terrorized the set during shooting. They threw other actors off with their ad-libbing, and once cornered costar Humphrey Bogart and stole his trousers. But they didn't figure on James Cagney's street-bred toughness. The first time Leo Gorcey pulled an ad-lib on Cagney, the star stiff-armed the young actor right above the nose. From then on, the gang behaved.
Some segments of this movie were remade and modified for the feature film Home Alone (1990) and its sequel. In the two movies, Kevin watches them as "Angels with Filthy Souls" and "Angels with Even Filthier Souls".
For years, viewers have wonder whether or not "Rocky" Sullivan (James Cagney) really turned yellow as he was being strapped into the electric chair. Some have wondered if he was faking it in order to keep his promise to Father Jerry. When asked about the scene years later, Cagney says he chose to play it in such a way so that the audience could make their own decisions as to whether or not he was faking.
The moment in which Rocky forces a trailing hood to take his place inside the phone booth in the pharmacy to get killed was inspired by the death of New York gangster Vincent "Mad Dog" Coll. In the real incident, Coll was locked in a gang war with Dutch Schultz. During the war Coll hid in an apartment above a pharmacy and would only come out to go into the pharmacy and call his girlfriend from the phone booth. Schultz found out about this and when Coll went to make his routine phone call, two of Schultz's gunmen walked in and shot Coll to death.
An architect by the name of Lewis Pilcher designed the death house - it went into service in the early 1920s. The building is still there at Sing Sing. On Google Earth, zoom in on the prison, and look at the southwest corner by the river. The building with two wings and a diamond-shaped structure in the middle is the infamous structure.
The story was written by Rowland Brown as a project for James Cagney at Grand National Pictures, the independent studio Cagney had signed with in 1936 after winning a breach-of-contract suit against Warner Bros. The original plan had been for Brown to write the full script and direct the film, but when Warners won back Cagney's contract on appeal they bought Brown's story for Cagney but assigned John Wexley and Warren Duff to do the screenplay and Michael Curtiz to direct.