@Dominions Son
All of the sources I listed above put the origin of the meter and the entire metric system to the French Academy of Sciences post French Revolution.
In the Wikipedia article on the history of the metre they put the concept as being over a hundred years earlier:
In 1670 Gabriel Mouton, Bishop of Lyon, also suggested a universal length standard with decimal multiples and divisions, to be based on a one-minute angle of the Earth's meridian arc or (as the Earth's circumference was not easy to measure) on a pendulum with a one-second period. In 1675, the Italian scientist Tito Livio Burattini, in his work Misura Universale, used the phrase metro cattolico ("universal measure"), derived from the Greek μέτρον καθολικόν (métron katholikón), to denote the standard unit of length derived from a pendulum.
However, it seems it was the French Academy of Science that came up with the exact length of the modern metre. They did so because there were dozens of different measurements and measurement systems within France at that time, although there doesn't appear to be a ready list of them all on the Internet. Since then the metre has been redefined a few times.
Due to the naming system, and the fact the modern metre closely resembles what was promoted back in the mid 1600s it's clear that's what they started from. Was the system in use somewhere at that time? - that question is not answered anywhere I can readily find on the Internet.
Even the link to NIST you give says the metre name and definition going back before the 1791 definition by the French Academy.
So it's clear the FAS did not invent the metre, they simply came up with a new length by a way of giving it an exact measurement based on the earth, a method promoted over a century earlier. Yes, the FAS promoted it's use across France, but one has to wonder if it was already in use somewhere for them to know about it a century after it was first proposed.
I'm off to the doc now.