Everyone rightfully points out Cagney's bravura performance, but Curtiz's direction is nearly flawless. Say what you want about Curtiz's auteurist credentials, but his direction in this film as is about as good as anything I've seen in the great decade of 1940s cinema.
Despite its corniness and over the top patriotism this is a well made film from the versatile director Michael Curtiz and a perfect vehicle for the great James Cagney, who could not only intimidate with his harsh gangster characters but could delight audiences with his song and dance. Nobody had better comedic timing then Cagney and he brilliantly shows it here. Walter Huston was great too.
Heavy on histrionics, not to mention factually inaccurate, but damned if it isn't highly entertaining! For once the Oscars got it right by (finally) awarding Cagney for one of his finest performances! His turn as George Cohan is full of emotion and gravitas as well as being on the money physically.