That wasn’t true in the 19th century. There weren’t that many self sufficient farmers left back then and the economy was heavily interlinked, especially after t

That wasn’t true in the 19th century. There weren’t that many self sufficient farmers left back then and the economy was heavily interlinked, especially after the rise of railroads. The economy was in a permanent boom and bust cycle e.g. the Long Depression (or the first Great Depression) lasted close to a quarter of a century.