The “Allandale House Historic Site,” also known as the Cunningham House on the Andrew Cunningham Farm, is located off IL St. Hwy. 125, just outside of Virginia, IL.
According to an article in the Journal of the Illinois State Historical Society (Vol. 28, No. 2, Jul., 1935) entitled “An Old Adobe House” ( http://www.jstor.org/pss/40187858 ), “Three miles northeast of Virginia, Illinois, at the edge of Sugar Grove, there stands a beautiful and spacious home built of adobe. So far as is known this house–“Allandale,” home of the Cunningham family for several generations–is the only adobe house in Illinois; nor is it probable that there is anywhere in the central states another house constructed of this material so commonly used in Mexico and the dry southwest. In 1834, Andrew Cunningham, a young Scotchman, left his native land to try his fortunes in America….”
According to http://genealogytrails.com/ill/cass/bios-c.htm#cunningh , Andrew Cunningham was born near Edinborough, Scotland, December 17, 1806. His parents were James and Marion (Wright) Cunningham, natives of Scotland, where they lived and died. His father was a baker and miller by occupation and owned and operated a flouring mill in the village of Bonnington, a suburb of Edinborough. Andrew was educated in his own country, where he learned the baker trade, and sailed for America March 14, 1834. He was married in Canada, in 1836, to Ellen Allen, who was also born in Scotland, in 1812. In 1835 he came to Cass County, IL, to look up a location and in the beginning of 1837 settled on his present farm at a place on Job’s Creek called Sugar Grove where he built a small house and established a tannery. The tannery was soon a thriving project, and as Cunningham’s fortunes rose, it was then he decided to erect a more substantial house.
According to Old Illinois Houses by John Drury reprinted by The University of Chicago Press , Chicago and London, 1977 ( http://penelope.uchicago.edu/Thayer/E/Gazetteer/Places/America/United_States/Illinois/_Texts/DRUOIH/Central_Illinois/27*.html ), the Andrew Cunningham House was built in 1852. Said to have been still in a fairly good state of preservation after almost a century of existence, this two‑story house is one of the most unusual dwellings in the state due to its adobe construction. In the years following, it attracted widespread attention because of the unusual building material. When he died in 1895 Andrew Cunningham left his heirs the diary of his trip the Illinois in 1835, his library, household articles, art objects, and one other reminder of him, a circular plot of ground in front of the adobe house which he ordered should never be touched as it contained original prairie grass, the six- to eight-foot high grass which covered the great, wide prairies of Illinois before the coming of the white man.
According to Wikipedia, the Andrew Cunningham Farm is located near the Cass County, Illinois, city of Virginia. The Cunningham Farm is listed on the National Register of Historic Places, one of only two such sites in Cass County. The farm is about two and a half miles east of Virginia. It has been listed on the Register since May 12, 1975. I do not know if the house is open for public tours, and I really could not find too much online about its present status or condition, but there is a sign on IL Hwy. 125 saying, “Historic Site: Allandale House,” so someone is trying to call attention to it.