Who sends postcards anymore? We do--and not just when we're traveling. Postcards have always been popular with tourists, but in the early 20th century they were also used like email is today, for quick communication. Mail was delivered several times each day in many places, so people would send messages like "My train is arriving a 3PM," or "I'd like to order a dozen eggs, a gallon of milk, etc." This set of five Philadelphia-themed postcards measuring 4x6 was created by Hidden City co-editor Peter Woodall.