This is for your information only! You can have your DNA analyzed for ethnicity and genetic matches. These cost money, take time, and have privacy implications.
There is a series of books about different ethnic groups in Michigan. You can find them in SmartSearch by searching for the ethnicity (e.g. Swede, Dutch, Finnish, etc.) and Michigan. Limit your results to books. Some of them are print only and some are e-books, available online. A couple of examples are below:
There are many books in this series. Search SmartSearch with the phrase "[ethnicity] in Michigan."