One winter John Thompson skis across the Sierra Nevada Mountains and creates a path upon which mail and people may travel, thus earning his nickname "Snowshoe Thompson."

Books about the origins of humanity dominate bestseller lists, while national newspapers present breathless accounts of new archaeological findings and speculate about what those findings tell us about our earliest ancestors. We are obsessed with prehistory-and, in this respect, our current era is no different from any other in the last three hundred years. In this coruscating work, acclaimed historian Stefanos Geroulanos demonstrates how claims about...