American public school districts declined in number from about 200,000 at the beginning of the twentieth century to fewer than 15,000 in 2010. Almost all of this decline was the result of consolidation of rural one-room schools, which were usually the only schools in their districts, into large-area districts. This movement is regarded by education historians as the product of a top-down political process in which local interests were steamrollered by state officials and the professional educational establishment. Implicit in this account is the idea that the one-room schools were doing a good job, except for being imperfectly bureaucratized.
My view of this transformation is different. The great majority of the consolidations had to be voted on by the residents of the districts involved or their locally elected representatives. Many districts refused for years to consolidate. The chief advantage of district consolidation was that it allowed rural and small-town children to be streamed from multiroom, age-graded elementary schools into high schools. The oneroom school was well suited for spreading basic literacy and numeracy across the continent, but it was inadequate for preparing students for high school in the twentieth century.
A way of testing my account is to look at the most persistent exceptions to the abandonment of one-room schools. The Amish are a Protestant sect whose members employ much of the agricultural and household technology of the nineteenth century. As American rural school consolidation reached the Amish (circa 1930–1960), most of them left the public school system and re-created the oneroom schools that were the dominant mode of American education in the nineteenth century.