fireplace-kitchen core seems to be a separate house nesting within the larger glass house. The building is essentially one large room filled with freestanding elements that provide subtle differentiation within an open space, implied but not dictated, zones for sleeping, cooking, dressing, eating, and sitting. Very private areas such as toilets, and mechanical rooms are enclosed within the core. Drawings recently made public by the Museum of Modern Art indicate that the architect provided ceiling details that allow for the addition of curtain tracks that would allow privacy separations of the open spaces into three "rooms". Mies applied this space concept, with variations, to his later buildings, most notably at Crown Hall, his Illinois Institute of Technology campus masterpiece. The notion of a single room that can be freely used or zoned in any way, with flexibility to accommodate changing uses, free of interior supports, enclosed in glass and supported by a minimum of structural framing located at the exterior, is the architectural ideal that defines Mies' American career. The Farnsworth House is significant as his first complete realization of this ideal, a prototype for his vision of what modern architecture in an era of technology should be. Architecture as an expression of the times The Farnsworth House addresses basic issues about the relationship between the individual and his society. Mies viewed the technology-driven modern era in which an ordinary individual exists as largely beyond one's control. But he believed the individual can and should exist in harmony with the culture of one's time for successful fulfillment. His career was a long and patient search for an architecture that would be a true expression of the essential soul of his epoch, the Holy Grail of German Modernism. He perceived our epoch as the era of industrial mass production, a civilization shaped by the forces of rapid technological development. Mies wanted to use architecture as a tool to help reconcile the individual spirit with the new mass society in which the individual exists. His answer to the issue is to accept the need for an orderly framework as necessary for existence, while making space for the freedom needed by the individual human spirit to flourish. He created buildings with free and open space within a minimal framework, using expressed structural columns. He did not believe in the use of architecture for social engineering of human behavior, as many other modernists did,