Prison carved folk art box / stamp box

The box is made from a solid piece of wood that has been hollowed out and the lid is carved with figures that have a naive lack of proportion.  4.5 inches by 2.5 inches by 1.25 inches.  Inside the lid it says, "Made by a prisoner at Joliet Penitentiary."  Inside is a piece of paper that adds it was made before 1900 and was great grandmother's - Mary Gross Obermann.