In 1879, a third major building was erected – a chapel and dining hall called the Greenleaf Building. It was named for O.H. Greenleaf of Springfield, MA, a yearly liberal contributor. The upper part of the building was accessible by stairs. Doors on either side of the tower provided entrance to the dining room. At the right of the chapel was a small room and at the left a library. A storeroom existed under the stairway. Funds saved from the school were used to build this structure. These were augmented by contributions of $650 ($18317 in 2020) from O.H. Greenleaf, Captain Ebenezer Morgan, and Deacon O.B. Grant of Stonington.