James Cagney did not receive an Oscar nomination for portraying Eddie Bartlett in The Roaring Twenties.
James Cagney obviously is no stranger to playing gangster roles, but this one's variation comes through the way Eddie Bartlett gets into the rackets to begin with. In The Public Enemy he was already an ambitious hood, in Angels with Dirty Faces he was literally the kid on the wrong side of the rail road track, and later on in White Heat he was already a psychopath. Here Eddie Bartlett starts out as a soldier in World War I, and only comes across crime as a way to make up for the time he lost while in a fox hole. In the early scenes of the film Cagney is good at just playing Eddie a pretty average guy who just is trying to survive in the war, and then later on attempts to find his place back in society which is harder than he expects. Cagney's very good in that he actually makes Eddie's path to crime a rather sympathetic one, by showing the path to be as almost something which he stumbles upon it. There is not an obvious ambition that Cagney portrays as Eddie begins to get involved in the business instead he shows it to be a very honest reaction of a man finding something he can do, no more than that.
Cagney does not compromise the unassuming beginning for Eddie even as he goes about becoming a gangster by setting up his own club, and furthering the illegal operations. Cagney plays Eddie from the start as a charming enough guy who seems conducive to friendship as long as you don't give him a reason to dislike you. There is definite likability that Cagney captures well with Eddie and I particularly like the chemistry he seems to strike up with anyone in his group particularly Eddie's old buddy Danny played by Frank McHugh and Eddie's bootlegging business partner Panama played by Gladys George. Cagney keeps Eddie, even when he is becoming a criminal, still a rather endearing sort as he keeps the central idea behind the cheat of an unpopular law rather than Eddie being a full time villain in the least. As Cagney did in many of his gangster roles, Cagney does not condemn his character for having some moral corruption, despite him being condemned by the codes and standards of the time. Cagney never makes Eddie just a thug and instead presents him as someone one can easily identify with given the situation he is in.
Now this is not to say Cagney keeps Eddie a constant throughout the film by any means. As the film progresses and Eddie becomes more powerful as a gangster Cagney effectively suggests the way Eddie does slowly grow a bit of an ego through a willingness to embrace all elements of the life. Again Cagney does this in a gradual fashion as it never feels as though suddenly Eddie has betrayed himself and instead manages to show the way the lure of the criminal life harms him. Cagney's good as he begins to show that sort of gangster confidence that narrows his personality as a man to the point that he fails to notice a few things the first being that his girlfriend Jean (Priscilla Lane) does not really care for him and perhaps more pressing that his later business partner George (Humphrey Bogart) is a bit of psychopath. Cagney still brings the needed nuance to to Eddie importantly an importantly conveys the revulsion in Eddie as he sees just how cruel George is. However with Eddie's time in the life becomes a capable gangster himself, when dealing with his rivals in the industry. Now these scenes of course are always great for Cagney as he's absolutely in his comfort zone. No one quite threatens and stares down as well as Cagney, but he also earned this transition from the less intense Eddie we knew from the beginning of the film.
There is a bit of a change up for Eddie's story as a gangster as he actually is forced to drop out of the life from the end of prohibition and losing his money due to the stock market crash. To make it all worse Jean leaves him as well. Eddie is left with being a taxi driver as his only means of support. Cagney is terrific in showing just the worn out husk of a man that Eddie has becomes after losing everything that he believed made himself great. Cagney's very moving though by alluding within his sorrow there remains a better man than when he was the king of world. Now here is when the marvel of Cagney's work comes in this film but really all of his best gangster turns, White Heat included despite playing a psychopath. That being he allows Eddie to be more than just a series of gangster mannerisms and a tough exterior. Cagney as per usual reveals really the man within the story. He avoids just being just a two dimensional caricature for the sake of a morality lesson. Cagney finds something more and that's the case here too as he so brilliantly rips your heart right out and you did not even see it coming. By the end of the film Cagney has carried us through Eddie's story and really made him a man to care about despite his shortcomings. When Eddie must meet his fate as a gangster it is made surprisingly poignant because Cagney showed that he was always more than that.