A rarity among barns, the T.A. Leonard barn is sometimes called a round barn although it is a polygonal shape. This style of barn was first built by Shakers in the 1800s and popularized in the 1880s. Round barns were encouraged at that time by agricultural colleges: circles have greater volume-to-surface ratios than square or rectangular shapes, reducing building costs. They also offer greater structural stability because they are built with self-supporting roofs which open vast storage space.