Just east of Boise, the Old Idaho State Penitentiary grew from a territorial prison built in 1870 into a large sandstone-walled complex that operated from 1872 to 1973. Prisoners quarried stone and helped construct many of its buildings, whose surviving cell houses reflect changing approaches to confinement over more than a century. More than 13,000 inmates were held here, including Harry Orchard and Lyda Southard. The prison was also marked by solitary confinement, hangings, escapes, and major riots in 1952, 1971, and 1973. After the last riot, inmates were moved to a new facility, and the site became a museum and historic place preserved by the Idaho State Historical Society.