From The Making of Casablanca: Bogart, Bergman, and World War II:
“I remember,” says film critic Pauline Kael, “my friends and I talked about when are the executives going to discover this guy [Humphrey Bogart]. It was early in his career, when he appeared in horror movies and all sorts of stuff that Warners threw at him. We liked him years before he got the leading roles. he was small, but he knew how to use every part of himself. By the late thirties, he was quite in charge of everything in his performance. He had a tension, like a coiled spring. You didn’t want to take your eyes off him.”
In The Maltese Falcon, as Dashiell Hammett’s detective Sam Spade, Bogart carried to the right side of the law the wary watchfulness, the cynicism, and the ambiguities that had infused his deadliest killers. “I think it was his very best performance,” says Kael, who was twenty years old in 1941 when she saw the movie for the first time. “Because you got a sense of the ambivalances in th eman, and he used all the tensions marvelously physically. I don’t think he could have been as good as he was in Casablanca if he hadn’t done the Falcon first, because he really discovered his powers in the Falcon. he created more tension in his scenes than he ever had before. And I think afterwards he drew on the qualities he had discovered in himself in the Falcon. So I think it was [John] Huston who brfought those things out. And [Michael] Curtiz benefited from them.”…
The arc of Bogart’s career at Warner Brothers can be seen in how and when he chose to fight Warner — and with what success. Bogart was suspended for refusing to play the part of the outlaw Cole Younger in Bad Men of Missouri … His suspension ended in June 1941, when George Raft, whose career decisions at Warners were unerringly wrong, refused The Maltese Falcon because “it is not an important picture.” And what would have happened if Raft had agreed to play Sam Spade? The odds are high that Bogart would have made a breakthrough in some other movie. The disillusionment, stoicism, and weary aloofness that he brought to the screen fit the heroes of a new kind of movie melodrama, film noir, too well to have gone unnoticed …
Warner Brothers could overuse and misuse its actors. It could dump Van Johnson and Susan Peters in 1942 and let MGM build their careers. But the studio would not have remained in business if it had missed the obvious. The Maltese Falcon had been immensely profitable, and George Raft was becoming more difficult with every role he was offered. In January 1942, Bogart demanded $3,000 a week and the right to do ten guest radio appearances a year. He was given a new contract, starting at $2,750 a week. After six years at Warners, Bogart finally had a star’s contract. Warner Brothers was stuck with him for seven years, and the studio began to look for a role that would turn him into a romantic lead.
On February 14, [Hal] Wallis sent a memo to Steve Trilling: “Will you please figure on Humphrey Bogart and Ann Sheridan for Casablanca, which is scheduled to start the latter part of April.” Six weeks later, Jack Warner wrote Wallis that George Raft was lobbying him for the role. Wallis held firm and Casablanca had the first of its three stars.

