Marquette and Jolliet, The First Europeans on the Chicago Portage

In the summer of sixteen seventy-three, a Jesuit priest named Jacques Marquette and a fur trader named Louis Jolliet paddled their canoes south from the Straits of Mackinac, through Lake Michigan, and into the mouth of the Chicago River. They were the first Europeans to document this particular geography, though the Potawatomi and their predecessors had been using it for far longer.

What Marquette and Jolliet immediately understood was the significance of what they were looking at. Between the Great Lakes drainage and the Mississippi River drainage, there was a low, nearly flat divide, so low that in wet seasons the rivers practically connected. A portage of less than two miles, in places less than one, would carry a canoe from the Chicago River into the Des Plaines River and from there into the Illinois River and from there into the Mississippi and from there to the Gulf of Mexico. The entire interior of the continent was accessible from this spot. You could travel from the Atlantic, through the Saint Lawrence and the Great Lakes, to the Pacific drainage without ever carrying your boat more than two miles overland.

Marquette's journals, preserved in Jesuit archives and held at institutions including the Newberry Library in Chicago, record his recognition of the portage's significance. He wrote that the place where the rivers nearly met was where a canal could one day connect them entirely. He was right, though he did not live to see it: Marquette died on his return journey in sixteen seventy-five.

The canal he envisioned opened in eighteen forty-eight. Chicago was incorporated as a city in eighteen thirty-seven, having grown from a few hundred people to roughly four thousand within several years. The geography Marquette recognized in sixteen seventy-three was the reason.