Background
The Wisconsin Glacier
"Although the canal was built in the 1800s, its story began over 12,000 years ago during the last Ice Age. A sheet of ice that was up to a mile thick (the height of the Sears Tower) covered most of Illinois. This Wisconsin glacier carved the Great Lakes and flattened the prairie plains of Illinois. As the glacier retreated, its meltwaters carved the Des Plaines and Illinois River valleys, creating a natural passageway from Lake Michigan to the Illinois River."
-The Canal Corridor Association
-The Canal Corridor Association
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"Continental Divide"
"Four thousand years ago, a subcontinental divide rose up to interrupt this passageway. This low ridge forced the Chicago River to flow east into Lake Michigan, and the Des Plaines to flow west into the Illinois and Mississippi Rivers. This divide, later known as the Chicago Portage, is key to the canal story." -The I&M Canal Shapes History |
Importance of the Chicago Portage
“The fact that we could connect through portage the Des Plaines River, the Illinois, ultimately the Mississippi, meant you could get from the Atlantic Ocean to the Gulf of Mexico via water, which was really the only practical way of traveling 150 years ago.” -Margaret Frisbie, Executive Director of Friends of the Chicago River |
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