From 1001 books:
"Pynchon's Mason & Dixon is, loosely speaking, a kind of "updated" eighteenth-century novel that reanimates the lives, loves, and adventures of the two astronomer/surveyors who drew the boundary line across America that would eventually be used to distinguish the slaveholding states from the free states and is still used to distinguish the South from the North to this day. The tale is narrated retrospectively by the Reverend Wicks Cherrycoke in 1786 -- visiting Philadelphia for the funeral of Charles Mason. Cherrycoke becomes a Boswell-like figure, chronicling the experiences of these two Englishmen in a foreign land. This, however, is no ordinary Age of Reason. Pynchon combines years of painstaking historical research with outrageous comic imaginings and supernatural flights of fancy. Frontiersmen turn into beavers on full moons, the Jesuits invent the modern coffee machine, and Benjamin Franklin gives demonstrations of electricity while dressed as the grim reaper.
For all the jokes, songs, riddles, whimsies, and anachronisms, Mason & Dixon is ultimately a poignant and profound meditation on the origins and cost of modernity. A sustained exploration of the relationships between technology, capital, myth, magic, violence, and folk culture, this is an epic, sprawling work. In Mason & Dixon, Pynchon creates an old world for our uncertain times."