I've run across two reasons in my research:
- this land was "free" for settlement about this time. I had relatives who came here for that reason.
- The area had huge logging operations where many men found work.
For general history, try doing a google search for Bingham or Solon Maine history - you might find some information. Somewhere I read that people from the Norridgewock/Fairfield, Maine got incentives for the free land to settle the state further north on a direct line to Canada.