The Great Disappointment 

As a young geology student, I had an assignment to map the slate beds of west-central Vermont and adjacent New York State. 

This area is known for its high-quality slate, and the manufacturing of roofing slate became an important part of that area's economy in the mid-1800s.

In my explorations of the area, I stumbled on an old church building, which appeared to be abandoned and boarded up. A sign indicated that it had been known as "William Miller Chapel".

I wondered about it. It seemed like a sturdy old building, typical of many structures one would encounter in rural Vermont and upstate New York. The roof, I noted, was sheathed in slate shingles, like many old buildings in that area. 

It was only later, when looking through a classmate's psychology textbook, that I learned that it happened to be the site of the Great Disappointment of 1844. The textbook used the story of the Great Disappointment as an example in the chapter on Cognitive Dissonance. 

William Miller 

The author of this great disappointment was William J. Miller (DOB February 15, 1782). Miller was a farmer, a military officer (War of 1812), a clergyman, an author, and eventually the leader of the Millerite movement.