In the spring of 1791 a soldier in the army of Major General Arthur St. Clair, pausing on his march through western Pennsylvania to view a prehistoric earthwork along the Monongahela, wrote in his journal This ancient work, from appearances, must have been built many hundreds of years ago, but who were the people at that time inhabiting this country? for what causes were they built? Here I am at a loss, yet I am not alone: still that can be of no satisfaction to me; but on enquiries of this nature, the mind is not satisfied with mere conjecture; it requires more substantial food, the food of certainty…[The ruins] must, I think, be attributed to the workmanship of man…but who they were, from whence they came, at what period they arrived, or where they have passed to, I believe we must ever remain in ignorance (Anonymous, 1810, p. 23-4).