The McElroys built their Octagon House in 1861 on the east side of Gough Street, on a lot that ran from Presidio Road (today’s Union Street) to Vallejo Street in Cow Hollow. The earliest known photograph of the Octagon House, taken in the 1870s after over a decade of development had begun to transform Cow Hollow, shows both Washerwoman’s Lagoon and the sand dunes.
Octagonal houses were quite the fad at this time, after first being popularized by an 1848 book titled A Home For All. Written and self-published by an amateur New York architect named Orson S. Fowler, the book advocated the building of multi-story eight-sided homes with windows on all sides. At least five other octagonal homes are also known to have been built in San Francisco during the mid-nineteenth century. The McElroys may have taken the inspiration for the floor plan of their approximately 1,620- square-foot two-story home from a plan published in the 1853 edition of Fowler’s book.