The fledgling U.S.A. had begun it's wartime campaigns for independence while American explorations continued. In 1778, Thomas Hutchins was exploring the Illinois lands.
He was amazed at the extraordinary bounty of natural growth, animals and forests of oak, walnut, etc. with huge trees. Even the Illinois ground was "a superior soil to any other part of North America that I have seen."
Those of us who had the pleasure of gardening in Illinois know that this natural resource has been conserved. While erosion due to primitive farming practices took a deep toll, there remain a few places where the original soil profile exists. Personally, during geological investigations, I measured the thickness of black loamy topsoil at 13 feet deep. This is extraordinary. Most places on Earth have just a few inches of topsoil. Rarely does it have so much organic humus to be naturally black and have such depth!
USDA Three Phase Diagram of Soil Types
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