Bogart and the Star System

During the classical "Golden Age" of Hollywood the big studios controlled the film industry. The Big Five studios of the time period were MGM, Paramount, 20th Century Fox, Warner Bros., and RKO. In the early years of cinema these studios were known to sign movie stars to contracts under their studios. The "star system" (or studio system) meant that actors were generally restricted to one particular studio that would sometimes lend their big stars to the other studios. These was a significant aspect of the industry at the time becuase it gave the studios exclusive rights to some of the well known actors that many Americans enjoyed seeing. Knowing this, the studios often used their contracted stars in several pictures a year, often playing "type casted" roles.
Studios having the liberty to cast their stars in as many films as they pleased often casted them in many films in genres they became quickly associated with. This impacted many stars in the Golden Era's careers. Errol Flynn became the adventure swashbuckler hero in most of his movies, Basil Rathbone generally played the smart villian type, Olivia de Havilland was the beautiful woman in distress, etc. All three of which can be seen in the genre film, The Adventures of Robin Hood, directed by Michael Curtiz (known for directing Casablanca). This often made it hard for actors to branch out from the type they were known for playing, even after the era of the star system was over.
Humphrey Bogart is a perfect examply of actors under the studio system. Initially signed under 20th Century Fox, eventually became contracted to Warner Bros. Studios. They worked Bogart constantly in "B movies" mostly the crime genre they were famous for. Between 1936 and 1941 Bogart starred in average of one film per two months. He became very much associated with the detective persona who followed his own rules but still had a moral character. Even though Bogart won an Academy Award and became the greatest actor according to the American Film Institute, he never really broke free of his type cast because of the star system.