Question: What is the square footage of this mansion in Duluth, Minnesota, operated by the University of Minnestoa Duluth as a historic house museum, indelibly linked with the Congdon name?

 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. Glensheen, the Historic Congdon Estate is a 27,000 square foot mansion in Duluth, Minnesota, United States, operated by the University of Minnesota Duluth as a historic house museum.  The home is a crowning example of design and craftmanship of the Midwest in the early 20th century. <SEP> The Warden's House Museum is a historic house museum in Stillwater, Minnesota, United States.  From 1853 to 1914 it was the official residence for the wardens of the Minnesota Territorial Prison, which became the Minnesota State Prison upon statehood in 1858.  The Washington County Historical Society has operated the house since 1941, making it the second-oldest house museum in Minnesota.  It was listed on the National Register of Historic Places in 1974 as the Minnesota Territorial/State Prison Warden's House for having state-level significance in the themes of architecture and social history.  It was nominated for being the only surviving structure of the prison's Minnesota Territory period and the chief remnant of its statehood years. <SEP> The Salisbury Mansion and Store is an historic house museum at 40 Highland Street in Worcester, Massachusetts.  The house was originally built on Lincoln Square in 1772 by Stephen Salisbury I with an attached storehouse from which he sold imported goods under the name "S. & S. Salisbury".  He and his brother Samuel had originally been in business together selling hardware goods in Boston, and Stephen moved to Worcester to expand the operation.  In 1820 the store was closed down, and the space was converted for residential use by the family, which occupied it until 1851.  Thereafter it served as a girls' school, tenant house, and then a gentleman's social club until 1929, when the building was threatened with demolition by the then occupants, the Worcester Lincoln Square Boys Club, who wanted to build more modern premises.  It was saved by local efforts and moved to its current location on the former Salisbury estate near the museum and next to Salisbury House.  It was donated to the American Antiquarian Society, which promptly gave it to the Worcester Art Museum, both of which were founded by Stephen Salisbury III.  The museum undertook to restore the much-altered building to its condition as of 1830, and opened it for group tours as a historic house museum. <SEP>  The Congdon name is indelibly linked with the Glensheen Historic Estate in Duluth, Minnesota. Chester Adgate Congdon (June 12, 1853 – November 21, 1916), lawyer and capitalist, was born in Rochester, New York, on June 12, 1853, his parents being Sylvester Laurentius and Laura Jane (Adgate) Congdon.