Jim Thorpe: the sports legend is one of the cons in the "telephone game".
All the locations and bearings radioed back and forth during the triangulation tracking of the gasoline truck, as it moves southwest across the Los Angeles basin, are accurate. They can all be found on a modern map of Los Angeles. Even the view of the Los Angeles City Hall shows up at the appropriate time.
At the time of filming of White Heat, Special Effects were not yet using squibs (tiny explosives that simulate the effects of bullets). The producers employed skilled marksmen who used low velocity bullets to break windows or show bullets hitting near the characters. In the factory scene, James Cagney was missed by mere inches.
Held the record for largest number of camera set ups in one scene; for the scene in prison mess hall where Cody Jarrett finds out his mother is dead.
If the surprise expressed by James Cagney's fellow inmates during "the telephone game" scene in the prison dining room appears real, it's because it is. Director Raoul Walsh didn't tell the rest of the cast what was about to happen, so Cagney's outburst caught them by surprise. In fact, Walsh himself didn't know what Cagney had planned; the scene as written wasn't working, and Cagney had an idea. He told Walsh to put the two biggest extras playing cons in the mess-hall next to him on the bench (he used their shoulders to boost himself onto the table) and to keep the cameras rolling no matter what.
Ranked #4 on the American Film Institute's list of the 10 greatest films in the genre "Gangster" in June 2008.
The train robbery was filmed using the former Southern Pacific tunnel in Chatsworth, CA. The Line is now owned by Union Pacific and was the location of a tragic 2008 head-on collision that killed 25 people.
The unusually close relationship between Cody Jarrett and his domineering mother was inspired by real life bank robbers Kate Barker (aka "Ma Barker") and her sons.