Fort Wayne is, indeed, a valid example of a fort/town built to control a communication route rather than one built with hopes for expanding trade. Hey! Cut me some slack! I did the whole routine by memory!
(And, of course, the St. Mary is quite a bit smaller than the Auglaize, allowing canoe traffic in the eighteenth century, but not really usable by bateaux. Fort Wayne is also a slight anomaly in that it is a site where white settlers initially established the town because of its proximity to a native town. There are several other cities founded as trading posts next to Indian towns, but they are not a really common phenomenon.)
Iโm curious about Sacramento. Is the American really a navigable river?
Tom~