Juan Gabriel Vasquez in The New York Times:
Colson Whitehead’s novels are rebellious creatures: Each one of them goes to great lengths to break free of the last one, of its structure and language, of its areas of interest. At the same time, they all have one thing in common — the will to work within a recognizable tract of popular culture, taking advantage of conventions while subverting them for the novel’s own purposes. “The Intuitionist,” with its dystopian concerns and futuristic mood, gave way to the folkloric past of “John Henry Days”; “Zone One,” Whitehead’s contribution to the unquenchable American thirst for zombies, was his departure from “Sag Harbor,” with its coming-of-age feeling and concessions to nostalgia. His new novel, “The Underground Railroad,” is as different as can be from the zombie book. It touches on the historical novel and the slave story, but what it does with those genres is striking and imaginative. Like its predecessors, it is carefully built and stunningly daring; it is also, both in expected and unexpected ways, dense, substantial and important.
The central conceit of the novel is as simple as it is bold. The underground railroad is not, in Whitehead’s novel, the secret network of passageways and safe houses used by runaway slaves to reach the free North from their slaveholding states. Or rather it is that, but it is something else, too: You open a trap door in the safe house or find the entrance to a hidden cave, and you reach an actual railroad, with actual locomotives and boxcars and conductors, sometimes complete with benches on the platform. “Two steel rails ran the visible length of the tunnel,” Whitehead writes, “pinned into the dirt by wooden crossties. The steel ran south and north presumably, springing from some inconceivable source and shooting toward a miraculous terminus.” The trains pass at unpredictable times and go to unpredictable places, but that is obviously good enough for those wanting to flee the misery and violence of slavery: its sheer inhumanity, a word that in Whitehead’s unflinching explorations seems to fill up with new meanings.