I learned about Guvernor Morris in University studying the Constitutional Convention and was surprised by how prolific he was. Of all the regular speakers at the convention, he was the only one who did not go on to become a president or otherwise be remembered as a Founding Father.
My professor told us this was because of Morris' opposition to the War of 1812. That position made him very unpopular politically, and it led a lot of history book authors to write him out entirely.
Today, on r/TIL, I saw this story, which said Guvernor Morris died in 1816 from injuries sustained inserting a whale bone into his urethra to try to treat a bladder infection.
To me, that sounded exactly like something a yellow journalist would write, right around the time the country hated Morris the most. But the Wikipedia article seems to have two sources for the story.
Did Morris really die that way? Was it a hoax? Has anyone investigated?
Currently, historians are very certain Morris did indeed die from an infection after trying to use a whalebone as a catheter. There hasn't been any evidence that his death was sensationalized at all.
Your professor is correct, Morris was a bit unpopular after the war of 1812. During the war he advocated for Northern succession which may be a reason why scholars generally don't mention him.
Also earlier during the early 1790s, word was spread in America that Morris was not a supporter of the French Revolution. This was problematic at the time as Americans were excited for the French and believed they were on a path similar to their own. As he was the Minister Plenipotentiary to France from 1792-1794 it only complicated matters and it was rumored he was helping the crown (which was sort of true). After that he was marked as a monarchist.
If you are interested in Morris you should check out these books:
Gouverneur Morris: An Independent Life by. William Howard Adams
Envoy to the Terror: Gouverneur Morris and the French Revolution
To Secure the Blessing of Liberty: Selected Writings of Gouverneur Morris edited by J. Jackson Barlow
Morris's diary's of the French Revolution. (Several editions of his diaries can be found online on the internet archive or Google books.)