Why was this Sea in North America on Old Maps?

Here is yet another giant body of water on old maps of North America that turned out not to exist. I’ve covered a few others and they are all associated with the wish to find a quick passage to Asia but each has its own unique backstory.

RareMaps.com Sources
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Guillaume De L'Isle / Jean-Claude Dezauche 1783 - https://www.raremaps.com/gallery/deta...
Philippe Buache 1780 - https://www.raremaps.com/gallery/deta...
Guillaume De L'Isle / Philippe Buache 1763 - https://www.raremaps.com/gallery/deta...
Louis Jolliet 1689 - https://www.raremaps.com/gallery/deta...


Other Internet Sources
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https://www.oldworldauctions.com/info...
http://antiqueprintsblog.blogspot.com...
https://sea-of-the-west.info/title
http://www.biographi.ca/en/bio/fonte_...
https://collections.britishart.yale.e...

Book Sources
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The Phantom Atlas by Edward Brooke-Hitching

French Translations - Kevin Mallet

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