@DialMforMara I'd start with the relevant sections of the following articles on Wikipedia:
https://en.wikipedia.org/wiki/History_of_Wisconsin#Pre-Columbian_history
https://en.wikipedia.org/wiki/History_of_Milwaukee#History_to_1820
Then look up more info about the tribes and cultures mentioned.
The bit about Jacques Vieau and Angelique Roy and the Métis community in Milwaukee sounds pretty fascinating.