In the early 1960s, a group of construction workers gathered outside of St. Louis, Missouri.

Technically, they were in Illinois, but at this point in time, the land was so flat and

empty, it was hard to tell where one state ended and one began.

They were tasked with digging out the dirt for a freeway that was meant to run through

this otherwise undisturbed rural area.

The hardest part of the job was going to be raising these mounds that seemed to be concentrated

here.

This particular part of Illinois didn't have any hills.

It was flat for miles, and yet in this one area, a few square miles big, there were all

of these mounds, around 8 feet high and 30 feet long.

The workers didn't have much time to think about that, however, because they were on a schedule.

President Eisenhower had recently started a freeway initiative that was supposed to transform

American commerce and travel the way that railroads did in the 1800s, and there was a lot

of work to be done.

So they started digging out the land for the road, and at first the project went off without

a hitch, but once they got to the mounds, everything changed.

As the excavator cut into the mound and pulled the earth away, the contractors could not

believe what they saw.

The mound was not just full of dirt, but evidence of an ancient civilization.

There were materials for houses, bowls, cups, weapons, clothing, you name it.

Archaeologists were called to the site, and what they discovered was that this area,

this rural little area outside of St. Louis, was the largest city in America a thousand

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