This paper traces the development of graded and non-graded classrooms in the United States in the 19th and 20th centuries and describes the implementation of multiage classrooms at an elementary school in Hopedale, Massachusetts. After defining what is meant by multiage classrooms, the paper discusses the role of Horace Mann, who was then a secretary for the Massachusetts Board of Education, in implementing the first graded classrooms in the United States in the 1840s. It also reviews early criticisms of graded education, especially those voiced by John Dewey, who felt that graded classrooms were too confining and machine-like. The paper then addresses the influences on the move back to nongraded or multiage classrooms in the late 20th century, reviews recent research on multiage instruction, and presents the educational benefits of multiage classrooms. Finally, the personal experiences of an elementary school principal responsible for the implementation of multiage classrooms at her school are presented. (MDM)