Colson Whitehead won the 2016 National Book Award for fiction for Underground Railroad, the story of Cora, a young slave who escapes captivity in the South. In Whitehead’s novel the historical Underground Railroad is a literal rail network.
“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.”
And the stops along the way often are also excursions into the fantastic.
(Note for clarity: This is a different book than Ben Winters’ alternate history Underground Airlines.)