Time and Again
by Jack Finney
Simon & Schuster, 1970
Si Morley is selected, for reasons unclear, to take part in a top secret government project -- a blue-sky, nutty project, an attempt to time travel with no technology or weird physics. The project's founder believes that the only difference between experiencing the current point in time (1970, in the book), and any other time is purely in the mind; if you believe that you are in 1475, you will find that you are indeed in 1475. With a bit of practice and a bit of hypnosis, this is proven to be true.
Okay, this sounds a bit wacky -- both to us and to Si. But once Si is actually in his time of choice -- mid-winter in the New York of 1882 -- the story moves into an excellent bit of historical fiction, surpassing Connie Willis for carefully-researched historical settings. While this usually, and correctly, identified as a work of science fiction, it is also an excellent and detailed history of everyday life in New York circa 100 years ago, and it is worth reading for that alone.
The writing style is a bit 1970s -- a little bit more plodding and egocentric than modern works, and steeped with a mild but constant and unapologetic sexism. However, it is not one of the works of hack science fiction that exploded onto shelves during the seventies, and and is both well-written and engaging. That said, it is science fiction only in the sense that it involves time travel rather than fairies or dragons; the 'science' is basically "believe it and it will happen", and even at that it could use some more filling out of the theory behind what's happening.
Not that Finney stints on the wordcount. My edition is 400 pages of slow moving plot and paragraphs packed with careful historical description. It is sometimes a bit much. Even so, it is a most excellent book, and if you have any interest in time-travel/historical fiction you should absolutely check it out. Be warned, this is not the SF pap tricked out with some interesting history facts and bloody violence that you often see (perhaps exemplified by Robert Lynn Asprin's Time Scout series); this is serious history, à la Connie Willis' Blackout, with the science fiction riding along solely so that we can have a modern person to identify with, and who can properly note all the tiny (and large!) differences in day-to-day life that are overlooked on political- and science-based history tomes.
Time and Again was written as, and works well as, a stand alone work. However, in 1995, 25 years after the original, Jack Finney published a sequel, From Time to Time.