Every inch of the New York office is governed by rules. There are regulations for book placement (general nonfiction on the post–Cold War is farthest from Caro’s desk; books on his immediate subject are kept closest) and the stacking of notebooks (new interview subjects, like the JFK speechwriter Theodore Sorensen, sit at the top of the heap, while the oldest interviews, like Johnson’s brother, Sam Houston, inhabit the bottom). The western wall contains only a giant outline—20 pages that get Caro from the beginning to the end of each book. “I trained myself to be organized,” he explains, pointing almost apologetically at his massive writer’s map. “If you’re fumbling around trying to remember what notebook has what quote, you can’t be in the room with the people you’re writing about.