Just south of Chicago sits a limestone quarry so massive it can be seen from space. Nearly 500 feet deep and over a mile wide, the Thornton Quarry is one of the largest excavations on Earth — and incredibly, a major highway runs directly through it. Drivers on I-294 pass sheer rock walls that drop hundreds of feet, while pilots use it as a visual landmark. But this giant pit isn’t just an industrial scar — it’s one of the most important engineering sites in America.<br /><br />In this episode, we trace the story from Chicago founder Gurdon Saltonstall Hubbard’s early land speculation to the rise of industrial limestone mining, the construction of the Tri-State Tollway, and the creation of the Deep Tunnel Project. You’ll discover how this former quarry became a key part of Chicago’s flood control system, capable of holding billions of gallons of stormwater — and why its history stretches back 440 million years to a tropical sea and even a meteorite impact.<br /><br />#Chicago #Engineering #History<br /><br />Support the Channel by becoming a member 👉 https://youtube.com/channel/UCzIZ8HrzDgc-pNQDUG6avBA/join<br /><br />IT’S HISTORY - Weekly Tales of American Urban Decay as presented by your host Ryan Socash. <br /><br />https://www.youtube.com/playlist?list=PL2NN2rktA4yMZ4vmNaA3KpsS5KXLj3xVN<br /><br />» Subscribe: https://youtube.com/@ITSHISTORY?sub_confirmation=1<br />» Listen podcasts: https://ffm.bio/itshistory<br /><br />» CONTACT<br />For brands, agencies, and sponsorships: itshistory@thoughtleaders.io<br />Click here to book a sponsorship with me http://thoughtleaders.io/reserve/its-history<br /><br />» DISCLAIMER<br />Some media elements in this video are used under the fair use provisions of U.S. copyright law (Title 17, Section 107) for purposes of commentary, criticism, and education. If you believe your image or content was used in a way that violates your rights, please contact us at copyright@videobrothersmusic.pl<br /><br />» CREDIT<br />Scriptwriter - Ryan Socash<br />Editor - Karolina Szwata<br />Host - Ryan Socash<br /><br /><br />» NOTICE <br />Some images may be used for illustrative purposes only - always reflecting the accurate time frame and content. Events of factual error / mispronounced word/spelling mistakes - retractions will be published in this section.
