Glensheen, the Historic Congdon Estate is a 20,000 square foot mansion in Duluth, Minnesota, United States, operated by the University of Minnesota Duluth as a historic house museum. Glensheen sits on 12 acres of waterfront property on Lake Superior, has 39 rooms and is built in the Jacobean architectural tradition, inspired by the Beaux-Arts styles of the era. The mansion was constructed as the family home of Chester Adgate Congdon. The building was designed by Minnesota architect Clarence H. Johnston Sr., with interiors designed by William A. French Co. and the formal terraced garden and English style landscape designed by the Charles Wellford Leavitt firm out of New York. Construction began in 1905 and completed in 1908. The home cost a total of $854,000, equivalent to more than $22 million in 2017. The home is a crowning example of design and craftmanship of the Midwest in the early 20th century.