Mies van der Rohe designed several buildings for the southern side Illinois Institute of Technology. Most of these structures employ a brick and glass infill system within an exposed steel frame. When he was given the opportunity to design Crown Hall in 1950, Mies deviated from the norm and built a totally different structure which no one had seen before.
Widely regarded as one of Mies van der Rohe’s masterpieces, Crown Hall refined the basic steel and glass construction style, beautifully capturing simplicity and openness for endless new uses. Creating this openness was achieved by the building having a suspended roof, without the need for interior columns. This created a universal space that could be endlessly adapted to new uses. While designing Crown Hall, Mies stayed true to his famous words, “less is more” and he considered the building to be the best embodiment of the maxim.
More info: https://en.wikipedia.org/wiki/S._R._Crown_Hall