Throughout the book, it is referenced that Moose's mom has to take piano lessons to also help pay the house.
On page 34, the text states that next to the cell house, there is this mansion which is the Warden's house .
On page 135, Scout says, "I'll trade you my extra glove for one of those convict baseballs." This shows that convict baseballs are pretty famous and that the convicts play.
According to the Author's Note, the prison guards did not earn that much.
According to Alcatrazhistory.com, the Warden lived right next to the cell house in a huge house.
According to the Author's Note, the convicts loved to play baseball on the recreation yard. Whenever a ball would go over the wall, if the gardener didn't throw it back over, the kids would get it. They were pretty popular.