Read the passage from The American Plague.All along the way Jefferson chafed at the jump in prices brought about by "harpies who prey upon travelers" returning to Philadelphia. Inns on the route had upped their rates; ferrymen were charging extra to transport people and carriages across rivers. In the end, Jefferson estimated that it cost him nearly eighty dollars just to get to Germantown.What was the cause of the jump in prices?

The passage says the higher prices affected travelers returning to Philadelphia during the yellow fever outbreak, and Jefferson describes people taking advantage of those fleeing the city. The outbreak caused people to travel away from Philadelphia, leading inns and ferrymen to raise their rates. The ferry boats were one service that cost more, not the overall cause of the price jump.

AI-written and checked against the verified answer.