Hooray!!! I have just discovered that there are 202 volumes of 170 titles of Michigan County Histories available online, fully digitized to allow all word searches!
From the website: "The Michigan County Histories collection is a collaborative effort of Michigan's Council of Library Directors. The collection is projected to provide access to 192 histories dating from 1866 to 1926. There are 202 volumes in 170 titles currently online."
There is a very simple to use search engine that brings up a photo of the actual book pages required. You can search for keywords, phrases, full names, surnames, locations, events, etc. Boolean searches are also allowed. You are also given the proper book description of title, author, publication date, and so on, to be able to cite your sources properly.
This is such an important find for New York State researchers because so many people from New York were involved in the westward migration, and some settled in Michigan for a while on their trek to the west.
I searched for phrases like "white creek", "cambridge, washington", "shaftsbury", "hoosick", etc. and came up with hundreds of hits. This is going to help flesh out the Old Cambridge District collection greatly!
Here is the website: http://www.hti.umich.edu/m/micounty/
Have fun!!! Now if only all states would do this. Hmmm.