Just a quick resource tip... check http://openlibrary.org
if you're looking for older VR books. I'm not sure what the push was back then, but many Massachusetts towns had VR books published in the mid-1800's. I've had great success finding these books out there and I'm able to use these as source material in my tree.
The trick is to click the "Show only eBooks" button under the search box. This will only show you those books that have been scanned and are available for online or downloadable reading. I try to save them whenever a PDF file is available.
Good luck & happy hunting!