Built in 1886, the Main Building served as the nerve center of the State Public School for Dependent and Neglected Children during that institution’s 60-year history. From 1945 to 1970, it served as the Owatonna State School, an institution for educable mentally retarded children. Designed in the 19th Century Norman Romanesque style, it remained significant after the state of Minnesota closed the institution in 1970. The city of Owatonna purchased the building in the spring of 1974, and in 1975 local citizens secured recognition of its historical and architectural significance through its addition to the National Register of Historic Places.