Ms. Bacall was an 18-year-old model in New York when her face on the cover of Harper’s Bazaar caught the eye of Slim Hawks, Howard Hawks’s wife. Brought to Hollywood and taken under the Hawkses’ wing, she won the role in “To Have and Have Not,” loosely based on the novel of the same name. Ms. Bacall’s love affair with Humphrey Bogart began with an impulsive kiss. While filming “To Have and Have Not,” he had stopped at her trailer to say good night when he suddenly leaned over, lifted her chin and kissed her. He was 25 years her senior and married at the time to Mayo Methot, his third wife. Bogart returned to his wife several times before he accepted that the marriage could not be saved. He and Ms. Bacall were married on May 21, 1945, at Malabar Farm in Lucas, Ohio, the home of Bogart’s close friend the writer Louis Bromfield. Bogart was 45; Ms. Bacall was 20. In 1947, as the House Un-American Activities Committee investigated Americans suspected of Communism, Ms. Bacall and Bogart were among 500 Hollywood personalities to sign a petition protesting what they called the committee’s attempt “to smear the motion picture industry.” The couple flew to Washington as part of a group known as the Committee for the First Amendment, which also included Danny Kaye, John Garfield, Gene Kelly, John Huston, Ira Gershwin and Jane Wyatt. Ms. Bacall’s first son, Stephen H. Bogart (named after Bogart’s character in “To Have and Have Not”), was born in 1949. A daughter, Leslie Bogart (named after the actor Leslie Howard), was born in 1952. She was also “den mother” to the so-called Hollywood Rat Pack, whose members included Bogart, Frank Sinatra, David Niven, Judy Garland and others. (It would evolve into the better-known Rat Pack whose members included Sinatra, Dean Martin and Sammy Davis Jr.) Bogart was found to have cancer of the esophagus in 1956. Although an operation was successful — his esophagus and two lymph nodes were removed — after some months the cancer returned. He died in January 1957 at the age of 57. She moved to New York in 1958 and, three years later, married Mr. Robards, settling in a spacious apartment in the Dakota, on Central Park West, where she continued to live until her death. They had a son, the actor Sam Robards, and were divorced in 1969.