Most Americans, I think, will not follow Posner or Klein in their rejection of American continuity. Gone With the Wind is still Americans' all-time favorite film, for example, despite being made a 'hundred years' ago in 1939 about the Civil War a 'hundred years' before that. The themes of community, honor, culture, love, war, and loss of the 19th century still connect through a story told in the 20th century to us now in the 21st. It's a great service movie-making does to put the history of each preceding generation on screen, to give a sense of our continuity and proximity.
For that matter, a hundred years—even two-and-a-half—is not so long. Consider this amazing fact from G. Edward White's biography of Supreme Court justice Oliver Wendell Holmes:
Holmes himself, born in 1841, still wearing high collars and swallowtail coats in his nineties, seems anything but a modern judge, even though one of his law clerks, Alger Hiss, died only in 1996. In some respects it seems easier to believe that Holmes knew John Quincy Adams, the sixth president dent of the United States, than that he worked with a man who lived into the 1990s.Incredible. I might have traveled to New York during college to try to meet Hiss before he passed, which, by just three more introductions, would have connected me to a founding father. They might as well be in the phone book.