I grew up with the public fascination of the Kennedy assassination. It's spawned many articles, TV plots, etc. written with the notion of "What if..?" I wasn't interested in hearing another story about conspiracy theories or time travelers hoping to save JFK. 
 It was a while before I would give this book a tumble. I'm glad I did. 
 The core of King's talent doesn't center around his penchant for horror or his flights of fantasy; it's his ability to create good characters that the reader can truly get involved with. Jake Epping is a teacher who cares a great deal for the people around him. In the opening of the novel, we find him gripped with the story of Harry Dunning, a janitor seeking his GED. Harry's father killed everyone in the family but Harry when he was young. 
 When Al the diner owner shows Jake the portal to the past, Jake resolves to save Harry's family. After several attempts, he succeeds. The feeling of power, the ability to change bad to good, helps suck him into Al's dream: saving JFK to create a better world. This requires that Jake travel back to the Fifties (the portal only leads to one point in time, every time) and take up residence, trailing Lee Harvey Oswald's path until the Big Day (hence the book title). He accepts the mission. 
 Along his path in the past, Jake makes new friends, touches the lives of students, and falls in love with Sadie, a beautiful but straight-laced teacher. He also gets harsh reminders of how very different things were in the Fifties: people smoked like chimneys, racism was the norm, and singing Rolling Stone lyrics could nearly end a relationship. The story of Jake's new life is interwoven with his pursuit of Oswald. Sadie unbends and becomes part of his quest, helping him in the final confrontation. 
 King's talent at character creation, combined with his command of pop culture, immersed me in the story and the time period. Overall, 11/22/63 was a book that exceeded the concept it started with. 
 Spoiler below: 
 (view spoiler)[I would have given this novel five stars, but the ending disappointed me. When Jake returns to 'modern time', the world has gone to hell. Earthquakes, thunder, the works. He also encounters cosmic authorities who urge him to essentially undo his entire mission in order to save the present. By changing so many events in the past, he's warped the universe. While cosmic authorities worked well in Ur, I don't think they're as necessary here. King described enough events following JFK's survival to screw the world up without threatening the space-time continuum. The final echo of the love he and Sadie shared, though, was very sweet. (hide spoiler)]