Comme Guys and Dolls (), qui avait ouvert plus tôt dans la saison, The King and I de Richard Rodgers et Oscar Hammerstein II a été un succès immédiat et est devenu du jour au lendemain un classique. Il est devenu le musical de la saison avec la plus longue série et celui qui comptera le plus de revivals. Bien que le musical ait été accueilli par de très bonnes critiques, il est surprenant de noter leurs réserves sur la partition et sur la performance de Gertrude Lawrence qui jouait l’enseignante anglaise Anna Leonowens qui arrive au Siam pour enseigner aux enfants du roi du pays (Yul Brynner).
Mais la performance de Lawrence en tant qu’Anna peut être considéré comme un sommet dans une carrière de sommets. Elle a remporté le Tony Award for Best Leading Actress in a Musical pour son interprétation chaleureuse, malicieuse et charmante. Elle est décédée pendant la série à Broadway et The King and I fut un chant du cygne glorieux pour l’interprète glamour qui au cours de sa carrière a sublimé des chansons de Noel Coward, George Gershwin, Ira Gershwin, Cole Porter, Kurt Weill, et Rodgers et Hammerstein dans une série de spectacles légendaires.
The King and I opened on Broadway on March 29, 1951, with a wide expectation of a hit by the press and public. Both Hammerstein and Rodgers professed to be worried. The composer complained that most people were not concerned about whether the show was good, but whether it was better than South Pacific. Even the weather cooperated: heavy rain in New York stopped in time to allow the mostly wealthy or connected opening night audience to arrive dry at the St. James Theatre. Margaret Landon, author of the book on which the musical was based, was not invited to opening night.
Brynner turned in an outstanding performance that night, nearly stealing the show. Lawrence knew that the company was nervous because of her illnesses. The director, John van Druten, described how her opening night performance put all worries to rest: "She came on the stage with a new and dazzling quality, as if an extra power had been granted to the brilliance of her stage light. She was radiant and wonderful." The rave reviews in the newspapers lifted Lawrence's spirits, and she expected a lengthy run as Anna, first on Broadway, then in London's West End, and finally on film. Lawrence won a Tony Award for her leading role, while Brynner won the award for best featured (that is, supporting) actor. The show won the Tony for best musical, and designers Mielziner and Sharaff received awards in their categories.
De Lappe remembered the contrast between Lawrence's indifferent singing voice and the force of her performance: “I used to listen to Gertrude Lawrence on the public address system every night in our dressing rooms, and she'd get onto a note and sag down off of it. The night after I left the show to go into Paint Your Wagon, Yul Brynner gave me house seats and I saw her from the front and I was so taken by her. She had such a star quality, you didn't care if she sang off-key. She more than dominated the stage. Boy, was that a lesson to me.“
Lawrence had not yet discovered that she was dying from liver cancer, and her weakened condition was exacerbated by the demands of her role. At the age of 52, she was required to wear dresses weighing 75 pounds (34 kg) while walking or dancing a total of 4 miles (6.4 km) during a 3½ hour performance eight times a week. Lawrence found it hard to bear the heat in the theatre during the summer months. Understudy Constance Carpenter began replacing her in matinee performances. In the fall, Lawrence's strength returned, and she resumed her full schedule, but by Christmas she was battling pleurisy and suffering from exhaustion. She entered the hospital for a full week of tests. Just nine months before her death, the cancer still was not detected. In February 1952, bronchitis felled her for another week, and her husband Richard Aldrich asked Rodgers and Hammerstein if they would consider closing the show for Easter week to give her a chance to recover fully. They denied his request, but agreed to replace her with the original Ado Annie from Oklahoma!, Celeste Holm, for six weeks during the summer. Meanwhile, Lawrence's performances were deteriorating, prompting audiences to become audibly restive. Rodgers and Hammerstein prepared a letter, never delivered, advising her that "eight times a week you are losing the respect of 1,500 people". In late August, Lawrence fainted following a matinee and was admitted to New York Hospital. She slipped into a coma and died on September 6, 1952, aged 54. Her autopsy revealed liver cancer. On the day of her funeral, the performance of The King and I was cancelled. The lights of Broadway and the West End were dimmed; she was buried in the ball gown she wore during Act 2.
Carpenter assumed the role of Anna and went on to play it for 620 performances. Other Annas during the run included Holm, Annamary Dickey and Patricia Morison. Although Brynner later boasted of never missing a show, he missed several, once when stagehands at the St. James Theatre accidentally struck him in the nose with a piece of scenery, another time due to appendicitis. Also, for three months in 1952, Alfred Drake replaced Brynner. One young actor, Sal Mineo, began as an extra, then became an understudy for a younger prince, then an understudy and later a replacement for Crown Prince Chulalongkorn. Mineo began a close friendship and working relationship with Brynner which would last for more than a decade. The last of the production's 1,246 performances was on March 20, 1954. The run was, at the time, the fourth longest ever for a Broadway musical. A U.S. national tour began on March 22, 1954, at the Community Theatre, Hershey, Pennsylvania, starring Brynner and Morison. The tour played in 30 cities, closing on December 17, 1955, at the Shubert Theatre, Philadelphia.