An unbuilt historical concept. The Frank Lloyd Wright Foundation records that Wright had no site, client or budget for it. There is no active construction programme or appointed builder.
Read the original concept account ↗A city concentrated in one building
Wright presented The Illinois in 1956. The Frank Lloyd Wright Foundation describes a proposal for more than 100,000 occupants and over 18 million square feet of space, with road, rail and helicopter access. It was a historical vision, with no site, client or budget.
Concept source ↗Taproot and cantilevered floors
The structural idea combined a deep substructure, a concrete-and-steel central core and four buttressing wings. Floors would cantilever outward. Wright compared the arrangement to a rooted living structure, but the proposed resistance to wind was never validated through construction.
Concept source ↗Elevators at the edge of the proposal
The scheme imagined 76 elevators with five-storey cabs and atomic power. Those specifications describe Wright’s ambition, not an installed or tested transport system. The lift concept is one of the clearest separations between the drawing and an executable building design.
Concept source ↗Who designed it, and who would have built it?
Frank Lloyd Wright authored the concept. There was no appointed builder or active construction programme. A present-day rendering can explain the geometry, but does not supply missing engineering calculations, approvals or a delivery team.
Concept source ↗What would need to be resolved?
The following questions are our technical reading of the concept, not claims that the designers published or completed these checks.
A load-path idea is not a verified structure
A core and buttressing wings suggest a route for gravity and lateral forces to reach the ground. Verification would still require member dimensions, connection behaviour, realistic loading and site-specific foundations. A deep “taproot” does not by itself demonstrate adequate overturning resistance or acceptable sway.
Serviceability and human movement
A one-mile tower would require much more than checking ultimate strength. Engineers would need to evaluate acceleration, differential movement, lift travel and transfer times, refuge areas and emergency access. Multi-storey lift cabs introduce loading and circulation questions that a rendering cannot resolve.
Why the concept remains worth studying
The Illinois makes the relationship between density, transport and structure unusually explicit. Its value is in the questions it forces designers to ask, including how much urban activity can be concentrated at one address. It should be compared with built towers as architectural history, not placed in a forecast of towers expected to open.