11/22/63, by Stephen KingRead about the other titles on the list.
The horror author's new novel tells the story of Jake Epping, who is let in on the secret of a time-travel portal inside a local diner by its dying owner. The owner, Al, asks Epping to go back in time and complete one very important task – stop President Kennedy from being shot.
Discover why King ventured into this sub-genre.
Also see David Daw's list of five American presidents in alternate history.