architects - Louis Sullivan
First successful expression of the tall office building. Sullivan's functional analysis equates the building to a column, base, shaft and capital.First floor with large open spaces for merchandiseestablishments, banks, etc. Top floor for mechanical equipment. Shaft between floor offices, all essentially the same size and shape.

In the Wainwright Building Sullivan developed the expression for the tall office building which would be accepted by the Modern Movement as the model solution.

Sullivan's achievement is in the area of expression. His ornament, derived from nature and from geometry was close to Art Nouveau in Europe. Its organic nature, basic continuity, perhaps influenced a young man in Sullivan's office in his thinking toward "Organic Architecture"-Frank Lloyd Wright.