Who were the Cunningham boys and what happened to them? What’ the irony here?

The Cunningham boys were a part of the group Boo hung out with. When they got into trouble, the Cunninghams were sent away to industrial school, where they were reformed and received a great education. Mr. Radley refused to let Boo go to the school, and Boo was left stuck in the house while the other boys got engineering degrees..... all because his father believed that to let Boo go would be a disgrace.