The character of The Reverend Anthony Anderson was loosely based on the historical figure of Peter Muhlenberg, known as the "Fighting Parson of the American Revolution".
The scene near the end, where General Burgoyne (Sir Laurence Olivier) invites Richard Dudgeon (Kirk Douglas) and Mrs. Anderson (Janette Scott) to dine with him and his lady friend is based loosely on the historical fact that after the British surrender at Saratoga, General Burgoyne and the American commander, General Horatio Gates, and their staffs then ate a simple lunch together (shortly after 2 p.m. on Friday Oct.17, 1777).
Natalie Wood turned down the role of Judith Anderson because she didn't want to work with Kirk Douglas for "personal" reasons. After Douglas's death in 2020, nearly forty years after Wood's death, it was claimed that he had once raped her, whilst she was still in her teens. This has never been confirmed, however.
According to Gavin Lambert's biography of Natalie Wood, the reason why Wood refused to be in the film was because part of her pre-nuptial agreement with husband Robert Wagner indicated that they should not be separated for more than 2 weeks at a time. Taking a role in the film meant that Wood had to leave for England which would definitely make it difficult for both her and her husband to uphold this part of the agreement. However, according to biographer Suzanne Finstad, Wood's private reason for not wanting to be in the film was because she didn't want to work with Kirk Douglas. She was placed on studio suspension as a result.