I had a professor in architecture school who said that you couldn’t draw up a building properly at 1:100 scale until you had worked out all the details at 1:20. Whether or not this is true for architecture, Robert Caro demonstrates how well such an approach works for writing history. Throughout The Years of Lyndon Johnson, and most particularly in his fourth and latest volume, The Passage of Power, Caro zooms in and out without ever losing the complex whole he has so carefully built up. Immense as Caro’s project is, The Passage of Power demonstrates the logic of his decision to extend the project to a fifth volume (he originally planned only three). The first 47 days of the Johnson administration, in which the best version of the man took charge, culminate this volume and are well worth the several hundred pages Caro devotes to them. There will be plenty of space for “ruthlessness, secretiveness, deceit,” the worst aspects of Johnson’s character, in the Years to come.