No discussion of famed Loop architecture is complete without mentioning the boxy, metal-and-glass style of Ludwig Mies van der Rohe, whose functional, stripped-bare design became the standard for modern skyscrapers. The 1974 Kluczynski Building, part of the Chicago Federal Center, is a prime example. It demonstrates both the geometric, open spaces and starkly minimalist vertical I-beams he favored.
He designed many more buildings at the Illinois Institute of Technology in Bronzeville, on the South Side.