One of the greatest tough-guy personas of twentieth-century film, James Cagney worked hard to refine his image to meet his responsible Catholic background. The result was a complex set of characters who ranged from the hard-working immigrant striving to make his way in America, to the American hero of Cold War times who fought to preserve our way of life against Communist infiltrators. Cagney's various personas culminated in one as different from the others as can be imagined—he began to play characters on the edge of (in)sanity. It is his image as a tough guy, however, that is most enduring.

In 1933, during the filming of Lady-Killer, Darryl F. Zanuck sent a memo to his crew of writers in which he detailed the studio's requirements for the Cagney persona: "He has got to be tough, fresh, hard-boiled, bragging—he knows everything, everybody is...