Most, if not all, of the children who acted in this movie were from The Bachman Recreation Center of Dallas TX. It is a learning and activity center for handicapped persons.
Shawn Timothy Kennedy ("Voicebox Charlie") could actually talk. The twins in the unloading scene are his real-life brothers.
Filmed at a real summer camp. The kitchen crew were the actual camp kitchen staff.
This movie is based on the true story of Ron Jones. His 1976 book "The Acorn People" is about his counselor job at a summer camp for disabled kids.
The author of "The Acorn People" book, Ron Jones, had two other of his stories made into films: The Wave (1981), and One Special Victory (1991). He is best known as the original teacher of The Wave high school classroom experiment in extremism in 1967, and is featured in the Wave documentaries Lesson Plan (2010) and The Invisible Line (2019).