Jack Dawson and Rose DeWitt Bukater, the main characters from the 1997 film "Titanic," are not directly based on historical figures. They are fictional characters created by James Cameron, the film's writer and director. Cameron designed these characters to represent different social classes and perspectives aboard the ill-fated ship, thereby creating a love story that would serve as the central narrative of the film. While Jack and Rose themselves are not real, their story was influenced by the historical context of the RMS Titanic and the real people who were part of her voyage. Cameron drew upon the experiences of actual passengers and the well-documented accounts of the Titanic disaster to craft a narrative that would be both historically resonant and dramatically engaging. The film does, however, include portrayals of several real-life historical figures involved with the Titanic. This includes individuals such as J. Bruce Ismay, the managing director of the White Star Line (played by Jonathan Hyde); Molly Brown, a wealthy socialite and philanthropist (played by Kathy Bates); and the ship's captain, Edward John Smith (played by Bernard Hill), among others. It's worth mentioning that some elements of the film were inspired by anecdotes or characteristics of real passengers. For example, the story of the musicians playing as the ship sank is based on real events, while certain attitudes and societal norms depicted in the film reflect the reality of the early 20th century. In summary, while the love story of Jack and Rose is fictional, "Titanic" as a work of historical fiction is grounded in the real tragedy of the RMS Titanic, interweaving fact and fiction to create a compelling and emotionally powerful film.