Lauren Bacall for "To Have and Have Not" (1944), Bacall was so nervous that, to minimize her quivering, she pressed her chin against her chest, faced the camera, and tilted her eyes upward. This effect, which came to be known as "The Look", became another Bacall trademark, along with her sultry voice. Bacall's character in the film used Slim Hawks' nickname "Slim", and Bogart used Howard Hawks' nickname "Steve". The on-set chemistry between the two was immediate according to Bacall. She and Bogart (who was married at the time to Mayo Methot) began a romantic relationship several weeks into shooting. Bacall's role
Lauren Bacall the 1950s by appearing as the leading lady in a string of films that won favorable reviews. Bacall was cast opposite Gary Cooper in "Bright Leaf" (1950). In the same year, she played a two-faced femme fatale in "Young Man with a Horn" (1950), a jazz musical co-starring Kirk Douglas, Doris Day, and Hoagy Carmichael. During 1951–1952, Bacall co-starred with Bogart in the syndicated action-adventure radio series "Bold Venture". In 1953, she starred in the CinemaScope comedy "How to Marry a Millionaire", a runaway hit among critics and at the box office. Directed by Jean Negulesco and co-starring Marilyn Monroe