Early in this voyage of discovery, Verrazano came upon one of the barrier islands of North Carolina. He did not see any of the gaps between the islands, but did see what looked to be a vast body of water across what he took to be an isthmus of land. As the whole point of his exploration was to find a route past the Americas, the Pacific Ocean was very much in the front of Verrazano’s mind, and thus he jumped to the conclusion that that body of water was the Pacific. As he wrote in a letter to King Francis:
We called it Annunciato from the day of arrival, where was found an isthmus a mile in width and about 200 long, in which from the ship, was seen the oriental sea between the west [corrected from ‘east’ in the text] and north. Which is the one, without doubt, which goes about the extremity of India, China and Cathay. We navigated along the said isthmus with the continual hope of finding some strait or true promontory at which the land would end toward the north in order to be able to penetrate to those blessed shores of Cathay.”
By the end of the sixteenth century, most European geographers had rejected the idea of a large Sea of Verrazano lying across the middle of the North American continent, so the general consensus was that the two most likely possibilities for a water route west from Europe to China and the Indies were either by a “Northwestern Passage” around the northern coast of America, or by a route which began with the St. Lawrence River. It wasn’t clear to geographers if that route would end up in the supposed North Sea or would lead right across the middle of the continent to a “Western Sea.” This Western Sea would, of course, either be the same as or would lead to the Pacific Ocean.
This was a widely held belief at that time, and in particular it had become the “ever-constant opinion of a school of contemporary geographers, that the great river of Canada [St. Lawrence] issued from a lake which also poured its waters by another channel to the South Sea.” (Justin Winsor, Cartier to Frontenac, p. 99) That is, the thought was that if one went far enough up the St. Lawrence, one would come to a lake which not only was the source of the St. Lawrence, but also of a river which flowed westward to the Pacific.
In the early seventeenth century, French explorers and missionaries continued to make inroads in exploring the Great Lakes and the river systems feeding the St. Lawrence. At some point the French heard of a “Nation of Stinkards,” who came from a body of water which smelled foul and which rose up and down. This sounded to the French an awful lot like the Western Sea they were seeking, bringing them, they hoped, into contact with traders from Cathay.
In 1634, Jean Nicolet was sent to find these “People of the Sea,” sailing from Lake Huron into Lake Michigan and on to Green Bay, wearing a damask robe for his anticipated contact with the Chinese. While he didn’t find the Western Sea, he was convinced that he would have found it if he had been able to sail just three more days journey up a river which flowed into Green Bay. His belief in this may have come from rumors he heard about the Mississippi River, which one could get to by sailing up the Fox River, which flows into the southern end of Green Bay, then down the Wisconsin River, with only a short portage between them.
The Mississippi seems to have been the source of a number of tales, reported in the Jesuit Relations, which the French missionaries heard from the Indians in the following decades about a large river which lay to the west of Lake Superior. This river supposedly lay not too great a distance west of the Great Lakes, maybe eight days journey, though the distances varied. The French understood these tales as indicating that this river flowed into a salt water sea where could be found men who were like the French. While it is possible that there might have been some reports, which traveled along the Mississippi River, of contacts with the Spanish on the Gulf of Mexico, it is more likely that these reports came from a wishful-thinking misinterpretation of reports provided by eager-to-please Indians.
By 1669, the French had received clearer reports of the “Messipi” River, which flowed southward. They hoped it would flow to the Vermillion Sea, thus offering them a route to the Orient. Thus, Louis Jolliet and Father Jacques Marquette were sent out in 1673 to explore the river and see where it went. Jolliet and Marquette canoed down the Mississippi to its confluence with Arkansas River, at which point they realized it likely flowed into the Gulf of Mexico, and so they turned back.
All was not lost, however, for when they passed by the mouth of the Missouri River, flowing into the Mississippi from the west, the explorers thought that this might be the real route to the Western Sea. The Relation of 1672-73 (written by Father Dablon) gives this account from Marquette
“Pekitanoui (as they named the Missouri) is a river of considerable size coming from the Northwest from a great distance and it discharges into the Mississippi; there are many villages of savages along this river and I hope by its means to discover the Vermilion or California Sea....It would be a great advantage to find the river leading to the southern sea toward California and as I have said this is what I hope to do by means of the Pekitanoui according to the reports made to me by the savages. From them I have learned that by ascending this river for 5 or 6 days one reaches a fine prairie 20 or 30 leagues long. This must be crossed in a Northwesterly direction and it terminates in another small river---one which one may embark for it is not very difficult to transport canoes through so fine a country as that prairie. This second river flows toward the Southwest for 10 or 15 leagues after which hit enters a lake, small and deep. [That lake is] The source of another deep river which flows toward the west where it falls into the sea. I have hardly any doubt that it is the Vermilion Sea and I do not despair of discovering it some day.” (Vol. 59, p. 143)
This concept was confirmed by Louis Hennepin, who in 1680 was sent by La Salle down the Illinois River to the Mississippi River. On his trip Hennepin saw the Missouri, about which he wrote, in 1683, that the Indians informed him that “its source was found by ascending ten or twelve days journey to a mountain from which all these streams are seen flowing, that then form this river. They added that beyond this mountain the sea is seen and great vessels....” (From Louis Hennepin, A descripton of Louisiana. New York: John G. Shea, 1880, p. 344) In a book published in 1697, which expanded on his 1683 publication—much of the expansion being fabrication—Hennepin expanded on this with the assertion: “They told me further than from that Mountain [emphasis added] one might see the Sea, and now and then some great Ships..” (From English edition A New Discovery of a Large Country in America by Father Lewis Hennepin, 1698).
By that time, hope in a route to Cathay by heading to the north of the Great Lakes had faded both because of the lack of success in finding any western outlet from Hudson’s Bay or other northern waters, and also because by then the British had seized control of the area to the north with their Hudson’s Bay Company, founded in 1670.
As for the third alternative, a sea route heading west from the Great Lakes, there was no clear evidence, though there were suggestive reports. Whether such a route existed simply was not known, as Delisle shows by leaving the area west of the Great Lakes totally blank. Most maps had left this area blank, and making this a convenient place to put cartouches and inset maps—a common thing demonstrated in the Delisle map. Of course, it is such blank spaces on maps that allowed for continued, unfettered speculation, and this is exactly what we will find in the following decades. It is just in this hitherto blank area to the west of the Great Lakes that myriad conjectures about water routes to the Western Sea would appear in the eighteenth century.