The population of New France in 1760 is more usually estimated at 80,000 rather than 70,000. But the important thing to keep in mind is that the French settlements in the Midwest that Acajack is alluding to CONTINUED to develop after 1760, and in fact essentially developed after 1760, first under Spanish rule in the Spanish Louisiana (which was essentially managed by French local authorities, despite formal transfer to Spain in 1763), and then more strangely in the first decades of US rule over these territories after the Louisiana Purchase. For example St. Louis remained majority French in the first decades of the 19th century, and the French language remained spoken in the city until the end of the 19th century (there even existed 2 French newspapers in the city, Le Patriote and La Revue de l'Ouest).
Cap-Girardeau, in Missouri, on the Mississippi River, was founded in the 1790s under Spanish rule, and was another striving French community in the 19th century in the Midwest.
And of course there was also Detroit, where the French settlers remained the majority population until the early decades of the 19th century.
As for the Ohio Valley, unlike the Midwest it was not settled by French settlers, because it was Indian territory, and the colonial authorities of French Canada wanted to keep good relationships with the Indians for trade reasons and also to keep them as allies against the British. The French Canadian authorities did set up several French forts in the region however, including at Pittsburgh which was the French fort called Fort Duquesne. The French forts in the Ohio valley and south of Lake Ontairio were established there for military reasons, and not in order to colonize the area. The French settlements took place further west (Detroit, St. Louis, Cap-Girardeau, etc), and essentially after 1760.
On a side note, my high school in Southern France was twinned with the high school of Cap-Girardeau, and our city also has a cultural partnership with the Osage tribe of Amerindians, so that history is not forgotten in France.
That's the Osage memorial that was built in my hometown when I was in high school. Some of our classmates also went on a trip to Cap-Girardeau, but I didn't.
