[Help Needed] A novel about Saco Maine Thornton Academy?

In ninth grade, we had to read this novel about kids in prep school in Saco Maine. They attended Thornton Academy. I believe the first chapter involves the boys going down by the river.

Yesterday while in Maine, I drove by the Academy. The problem is that I have no clue what the novel was called or who the author is. It is driving me nuts thinking about it and google is of no help. I asked a girl who was in that English class, and while she remembered the story she couldn't remember the author or title.

I was wondering if one of you could help me.
All I remember is this guy arrived at his old prep school and began thinking about his school days.

Thank You,
Seldon