Bell bottoms. Beanie babies. Disco and the Atkins Diet. Fads are curious, strange creatures, and likely to reappear (especially in fashion) when least expected. I am not certain that this truism exists in architecture, for I have yet to spy the fad of octagon houses taking hold again. In mid-19th century America, the octagon house was hot, and yet complicated. This trend existed as a curious cross between a style and a type, and its main proponent intended to not reshape the built environment so much as improve the life of the common man. Orson S. Fowler, phrenologist (he examined people’s skulls, in the belief that personality and character were revealed by proportions of the head) and tireless promoter, is most closely linked with the development of the octagon house in America.
The origins of the octagon form, though, stretch back to religious structures constructed by the Greeks and Romans. Leonardo da Vinci espoused that the octagon was the ideal form for a church, and throughout the Renaissance it was often used in religious structures or ecclesiastical elements.William Kent, in his Designs of Indio Jones, used the form, and it was fairly popular in England for garden buildings, baths, and religious structures. The form remained almost solely the province of ancillary structures, and typically had no partition of the interior. Dutch settlers in New York brought the octagon form with them from Holland, and the earliest documented use of the form was an octagonal Dutch trading post built in 1683. Although it was chiefly used for church buildings, nearly 20 houses were built between 1680 and 1750 in the Hudson River Valley. 
Outside of New York, the octagon made appearances in several colonies, but the form remained “confined to a small segment of the population and was not publicly adopted on a large scale.” Williamsburg had an octagonal powder house, and churches continued to be built using the shape. Thomas Jefferson included the form in over 50 proposals, and built his retreat in Bedford County (Poplar Forest) using the shape.
America’s first professional architect, Benjamin Henry Latrobe (architect of the Pope Villa in Lexington, Kentucky), designed an octagon church in New Orleans in 1814. One of the most interesting (and practical) applications of the octagon form in building was the construction of octagonal tollhouses on the National Road in the 1830s. In 1831, the Pennsylvania legislature authorized the construction of six tollhouses, “choosing the form so that the tollkeeper would have a clear view of the road in both directions.”
Although the octagon form was known by the mid-19th century, and other architectural pattern books featured occasional octagonal designs, Orson Fowler, through his continual efforts to improve the life of the common man, brought the octagon house to the people. Fowler’s main concern was to enclose the most interior space for the least amount of money, and the octagon house was the “perfect solution…a house, beautiful by the form itself, that focuses on economy and function.”Another of Fowler’s key beliefs was the inclusion of porches all around the house to enjoy and view the surrounding countryside. The belief in the positive effect of a rural life inspired many writers and designers of his day.
The exact numbers of octagonal houses built in the United States has been as source of debate since the 19th century. Across the country, the “octagon house was built primarily from the late 1840s through the 1860s, though the greatest concentration of building was during the 1850s.” In addition to the chronological specification, octagon houses clustered in certain geographical areas, including New York (Fowler’s home), the Northeast, the Midwest, and California. Journals and promoters of the form proclaimed construction numbers in the thousands in the 19th century. In the 1880s, Orson Fowler himself took the trend to Colorado, leasing 5,000 acres for five years in the hope of building a colony of fruit growers that would live according to his philosophies on health and other social issues – and in octagonal buildings. Fowler filed a town plat under the name of Fowler Town and Development. The idea, alas, did not move forward.
Kentucky is not known for its abundance of octagon houses, but there are a handful of examples (I know of three). Octagon Hall in Simpson County is a two-story brick octagonal dwelling, built 1859-1860 for Andrew Jackson Caldwell. It is now a house museum (and apparently a paranormal attraction).
Octagon Cottage, in rural Barren County, Kentucky, is a one-story frame octagonal house built around 1850 by William Henry Edmunds, an attorney in Glasgow. Edmunds was a big fan of the octagon form, and in addition to his house, constructed four octagonal outbuildings: a kitchen, wash house, office, and carriage house. I don’t know whether any of these buildings are still extant.
The Sharpsburg Christian Church in Bath County, Kentucky, was designed and constructed by congregation member Simon Hedges in 1893. It is a frame, octagonal structure with an asphalt shingle roof, vinyl siding and a stone foundation. It is a little hard to see the octagon shape because of the squared tower entrance and additions to the rear of the church, but it is there!
By the late 1870s, the octagon form moved into American agriculture, and was “regarded with much favor by many intelligent agriculturists.” As Fowler had extolled, the octagon form made good use of building materials and interior wall space. I tend to think of the octagon as better suited for barns than houses…although Fowler claimed the octagon eliminated drafty hallways and dark corners, partition of the interior into useful, desirable spaces is difficult, and the chief complaint among people in the 1860s (the chief decade for the octagon fad) was about how complicated the shape made division of rooms on the interior. So perhaps the octagon is a house fad not likely to reemerge, and I shall have to be content with the musings and inventions of Buckminster Fuller…
 Rebecca Lawin McCarley. “The Octagon House in American Culture: The Influence of Orson S. Fowler in the Midwest.” (Master’s Thesis, Ball State University, 2001), 49.
 Ibid, 55.
 Ibid, 57.
 Ibid, 24.
 Ibid, 64.
 Cultural geographers tend to define the Midwest as Ohio, Michigan, Indiana, Wisconsin, Minnesota, Iowa, Missouri, and the astern halves of North Dakota, South Dakota, Nebraska and Kansas. In the master’s thesis by Rebecca Lawin McCarley, the Midwest was narrowed to include just Ohio, Michigan, Indian, Illinois, Iowa, Wisconsin, and Minnesota.
 McCarley, 45.
 Ibid, 77.