Construction on Lakeside
Construction on Lakeside
Gareth Clark
When most visitors walk up the long drive to Glensheen, they are immediately drawn to particular details, such a its rich red brick walls, beautiful landscape, carved stone accents, and a dramatic view of Lake Superior. What is often overlooked, is the story beneath the surface: a story of family, engineering, intentional environmental adaptation, and architectural creativity that made Glensheen not just a mansion, but an early 20th century infrastructural experiment.
The focus of this post is on Glensheen's structural design, and questions like: How do buildings communicate the values and vision of their architects and patrons not just through decor, but through the engineering decisions invisible to the casual visitor? Glensheen's exterior promises Jacobean-revival, but the structure within reveals something more modern, more practical, more efficient, and more reflective of the Congdon family's ambitions for permanence on the lakeshore.
Construction of Glensheen's main house began in 1905 and continued steadily until 1909, ultimetly producing a 39-room mansion designed in a Jacobean style closely related to Tudor-revival architecture. The stylistic choice makes the mansion appear older, and is an ode to the Congdon's English ancestry.
But within this historical exterior is another whole story, a story of steel.
Hidden beneath the brick is a steel-beam frame which is a structural feature more commonly associated with urban commercial construction than with residential lakeside mansions. This skeleton supports both the roof and the overall load of the building, freeing the designers to focus on the structural Jacobean facades without sacrificing stability. It also positioned Glensheen at the intersection of tradition and modernity: a house that looked centuries old but had all the efficiency of a new age.
One of the most compelling aspects of Glensheen's construction is the Congdon's attention to environmental infrastructure with intentionality. Duluth's lakeshore is beautiful, but is also harsh as anyone who has lived here would know: freezing winds, heavy snow loads, unstable shoreline soils, constant moisture and crashing waves all have to be taken into account.
In response many parts of construction were engineered with these factors in mind.
Along the mansion's south wall, the Congdons installed a large, reinforced concrete foundation. This was not common practice for residential architecture of the period. Concrete was still in a transitional phase between industrial and residential use, and offered superior stability on the shifting ground on the edge of Superior. Its inclusions suggest the Congdons, their construction supervisor J. C. Bush, and their architect Clarence H. Johnson Sr., understood the risks of building in such a location and took them seriously.
Unlike many Gilded Age estates built more for display than practicality, Glensheen was notably shaped by its environment. The area surrounding the house was carefully excavated and sculpted to withstand the surrounding landscape. The steel frame not only allowed more elaborate external detailing, it also increased the building's resistance to the wind coming of the lake. The concrete foundation added stability in an area prone to moist soil.
Gleensheen's structural design communicates not just aesthetic taste, but adaptation and foresight. It is a building that acknowledges its surroundings rather than imposing on them.
While Glensheen's exterior nods to Jacobean-revival architecture, its interior organization borrow elements from Baroque design, particularly in its approach to spatial hierarchy.
The ground floor; the home's public stage contains the most elaborate, grand, and expansive rooms within the greater estate, including the library, dinning spaces, and drawing room. These rooms are larger, more elaborately ornate and decorated and meant to impress guests. Their size was made possible, in part, by the steel beam structure, which allowed wider room spans without the heavy reliance of bulky load-bearing interior walls.
The private upper floors, by contrast are more humble, modest and practical. Structurally this spatial distribution reflects more modern social and structural norms of the Baroque and Gilded eras, rather than the Jacobean era.
When a visitor approaches the brick facade and enters into the structure of Glensheen, a larger story emerges about the family's influence and power in the Great Lakes region at the turn of the 20th century. The Congdon family's wealth, derived from legal work tied to industrial development, allowed the family to commission a house that reflected both stability and progress, in Duluth, an area they wished to have a hand in developing further.
The infrastructural systems such as the Glensheen water reservoir, coal delivery system, and reinforced foundation represent a desire for autonomy. In a region where nature held immense power, the Congdons built a home that positioned them above the vulnerabilities of the environment. In this way, Glensheen's structure becomes a quiet but potent monument to industrial ambition reflected by both their social status and Superior's surface.
Visitors often leave Glensheen speaking about their extensive art collection, grand library, or green breakfast room, but the structural design deserves equal attention, even if the green room is magnificent. It is the hidden architecture; the steel bones, the concrete foundation, the self-contained infrastructure, make Glensheen not only beautiful but enduring.
By blending historical style with modern engineering, the Congdon's created a home that performs tradition while living in the present, and enduring into the future. The design choices reveal a family deeply concerned with image, permanence, and the region. In this way, Glensheen becomes more than an estate; it becomes a conversation between aesthetics and engineering, environment and ambition, and finally, between the seen and unseen.
Understanding Glensheen's structural design invites us to appreciate the mansion not just for what it looks like now, but for how it was built, and what those choices reveal about the people who imagined it.
Sources:
Congdon Family papers, U6192, Archives and Special Collections, Martin Library, University of Minnesota Duluth.
Glensheen. “Glensheen Mansion: Historic Congdon Estate: Take A Tour.” Glensheen, October 31, 2025. https://glensheen.org/.
Moran, Kenneth J.. 1978-07."Exterior of Glensheen." Archives and Special Collections, Kathryn A. Martin Library, University of Minnesota Duluth, Accessed December 10, 2025. https://umedia.lib.umn.edu/item/p16022coll484:3026
Moran, Kenneth J.. 1983-03."Glensheen's library." Archives and Special Collections, Kathryn A. Martin Library, University of Minnesota Duluth, Accessed December 10, 2025. https://umedia.lib.umn.edu/item/p16022coll484:1002
"Glensheen shoreline and grounds from Lake Superior, including main house, beach, and part of boathouse. The beach is covered with snow." Archives and Special Collections, Kathryn A. Martin Library, University of Minnesota Duluth, Accessed December 10, 2025. https://umedia.lib.umn.edu/item/p16022coll524:16
1907 - 1908."Construction of Glensheen pier and boathouse, construction materials on pier." Archives and Special Collections, Kathryn A. Martin Library, University of Minnesota Duluth, Accessed December 10, 2025. https://umedia.lib.umn.edu/item/p16022coll524:48
Moran, Kenneth J.. 1978-07."Aerial photograph of the Glensheen estate, its buildings, grounds, and the nearby lakeshore." Archives and Special Collections, Kathryn A. Martin Library, University of Minnesota Duluth, Accessed December 10, 2025. https://umedia.lib.umn.edu/item/p16022coll484:3018