There is a scene in which Anna quotes President Abraham Lincoln as having said the following: "True progress must bear some relation to man's character. It must have its roots in his heart." According to the American Film Institute Catalogue, the veracity of this quote cannot be verified since it does not appear in any of Lincoln's major speeches or writings. According to Twentieth Century-Fox records, studio head Darryl Zanuck sent a memo to producer Louis Lighton and director John Cromwell that said, "If we cannot find a great Lincoln quote we should write one."

In the film, The King writes a letter to U.S. President Abraham Lincoln offering him a gift of elephants for the purpose of multiplying in North America. The real King Mongkut did indeed write such a letter, though it was actually sent to then President James Buchanan. However, since Abraham Lincoln was elected the new president of the United States by the time the letter arrived, it was Lincoln who responded with his polite decline of the unique offer.

In the film, Anna's young son Louis dies in a horse riding accident while in Siam. In reality, no such accident ever happened to Anna's son. In fact, young Louis went on to return to Siam later in his life and become a cavalry officer. He ended up outliving his mother.

Anna Leonowens' stories have always been controversial with the Thai government. From the time her original writings came out in the 1800s when the country was still known as Siam, the government objected to her depiction of the King and culture as "barbaric." The film versions over the years have been generally unwelcome there.

When Rodgers and Hammerstein were ready to mount their musical stage version of Anna and the King of Siam called The King and I in the early 1950s, Rex Harrison was interested in playing The King. He even auditioned to play the role on Broadway for the famed musical team. "I sang some songs for them," said Harrison in his 1975 autobiography Rex, "but they didn't like me, and I didn't get it."

By the same token, the composer of the original score for Anna and the King of Siam, Bernard Herrmann, also found himself unwanted when Rodgers and Hammerstein were creating their musical The King and I. According to the 1991 book A Heart at Fire's Center: The Life and Music of Bernard Herrmann by Steven C. Smith, Herrmann offered all of the research he had already done on Siamese music to the musical team, but they didn't want it. They were "not interested in Siamese music" according to Herrmann.

According to the AFI Catalogue, the original cut of Anna and the King of Siam ran two hours and forty-one minutes. Darryl Zanuck promptly had the film re-edited and cut down.

An article in Time magazine dated March 24, 1947 points out that Anna and the King of Siam was allowed to be shown in its entirety in Thailand at the time of its release despite the fact that "leading Siamese critics and historians had taken pains to point out that it was more than 75 per cent inaccurate."

Famous Quotes from ANNA AND THE KING OF SIAM

"Mem, if I tell King he breaks his promise, I will make anger in him. I think it is better if I make anger in him about larger matters."
- Prime Minister Kralahome (Lee J. Cobb), to Anna (Irene Dunne), after she reminds him that The King has not kept his promise to give her a private house.

"Do as you wish, Mem. But remember, you are not the only one with temper. The King has temper, too."
- Kralahome, to Anna

"You do not look like scientific person for teaching of school. How old shall you be?"
"I am 150 years old, your Majesty."
- The King and Anna

"You not afraid to tell King something is not his business?"
"It would not be a compliment to His Majesty if I were afraid of him."
- The King and Anna

"I have 67 children. Not many. I began marriage a little late."
- The King, to Anna

"How can King be wrong and woman be right? I ask you that. How?"
- The King, to Anna

"They think you wear dress like that because you're shaped like that down there."
- Lady Thiang (Gale Sondergaard), to Anna, noticing the large hoopskirt of her dress.

"Take a lesson from her, my friend, and you'll never give up on anything."
- The King, to Kralahome, talking about Anna.

"Please stop calling me 'Sir!'"
"I call you 'Sir' so you will not be lowly like a woman."
- Anna and The King

"Wherefore have you decorated yourself better than all rest? Shall it be for my observation?"
- The King, to Anna

"Herewith shall be list of subjects for you to bring up for talk. Because on such subjects I am very brilliant and will make fine impression."
- The King, to Anna

"You can't refuse her a trial. There must be a law in this."
"I am the law."
- Anna and The King

"Et cetera, et cetera, et cetera..."
- The King

Compiled by Andrea Passafiume