"Plum Orchard Mansion". List of Classified Structures. National Park Service. January 14, 2009. Archived from the original on May 21, 2011. Retrieved January 15, 2009.
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"Plum Orchard Mansion". List of Classified Structures. National Park Service. January 14, 2009. Archived from the original on May 21, 2011. Retrieved January 15, 2009.