completed in 1890, was the first ever steel-framed skyscraper in the world. Another characteristic of his designs that revolutionized modern architecture is his invention of the urban office block floor plan as we know it. As commissions multiplied, Burnham and Root had the opportunity to experiment and refine their style to create an entirely new aesthetic that was free of historical or European influences. Such buildings as the Great Northern hotel (1892), the Argyle and the Pickwick demonstrate Root's singular style.

In 1890 Chicago