Milton House, end of the line for the underground raolroad. 
There was a short-lived college in the late 60s and early 70s on Mackinac Island in Michigan. I think it was just called Mackinac College. My dad went there. The college was created by the Moral Re-Armament/Up with People (Buchmanism) movement, and apparently about half of the students didn’t learn this until they were already there. There was conflict and the students sort of split into factions. I’m not sure exactly what happened in the end, but the college went bankrupt. The campus was later turned into the Mission Point Resort.
I might go ahead and start a Wikipedia stub about it. There doesn’t seem to be anything. There’s a book about the conflict called “Quasi: a Brief on Ideology,” but it was written by a former student and I don’t know if it was published by a major house.
Wasn’t there also a defunct college purchased by the Transcendental Meditation organization that became Maharishi International University or something similar?
The Mary Allen Seminary , in Crockett, TX. Closed down due to financial problems in the early 1970s, IIRC.
I happened to be passing through Crockett, saw it, and thought it would make a great Terracache location. If you’re into geocaching, go log it: TC7TK
More info here.