Post Office - Canastota NY The historic post office building in Canastota, New York "was designed and built in 1940, and is one of a number of post offices in New York State designed by the Office of the Supervising Architect of the Treasury Department, Louis A. Simon. It is a one story, three bay steel frame building with facades of red brick laid in common bond in the Colonial Revival style. It features a gable roof crowned by a square, wooden cupola. The interior features a 1942 mural by Alison Mason Kingsbury titled "The Onion Fields.""