<P> The film is notable for being the ninth and final on - screen pairing of Tracy and Hepburn, with filming ending just 17 days before Tracy's death . Hepburn never saw the completed film, saying the memories of Tracy were too painful . The film was released in December 1967, six months after his death . </P> <P> In 2017, the film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant". </P> <P> Joanna Drayton's (Katharine Houghton) unannounced early return from a Hawaiian vacation causes a stir when she brings her new fiancé to her childhood upper - class home in San Francisco . He is John Prentice (Sidney Poitier): a widowed, black physician . Joanna's parents--newspaper publisher Matt Drayton (Spencer Tracy) and his wife, art gallery owner Christina Drayton (Katharine Hepburn)--are purported liberals who have instilled in her the idea of racial equality . But although they try to hide it, Joanna's parents and in particular her father are initially upset that she is planning to marry a black man . The Draytons' black maid, Tillie (Isabel Sanford), is even more horrified, suspecting that John is trying to "get above himself" by marrying a white woman . </P> <P> Joanna is oblivious to the reactions of her parents . They are unsettled by her engagement with John since they never thought that her choice would be a black man, and further unsettled by John's decision that if Joanna's parents do not accept the engagement that day, that he will end it . </P>

Who plays tilly in guess who coming to dinner