The architects who, rebuilding Chicago after the fire of 1871, invented the tall office building: a steel skeleton, fast elevators, broad “Chicago windows” and a clear, often tripartite façade.
Chicago’s great fire of 1871 and the city’s spectacular growth as the rail hub of the continent created a boom in commercial building in its compact Loop. Land prices pushed buildings up; the passenger elevator (Otis’s safety elevator was demonstrated in 1854, the first passenger lift installed in 1857) made height rentable; and the iron and then steel frame, fireproofed with terracotta, made it possible. William Le Baron Jenney’s Home Insurance Building (1884–85) is conventionally named the first skyscraper because a metal frame carried much of its walls.
The transition can be read in two buildings by Burnham & Root. The Monadnock (1889–91) is a sixteen-storey slab of load-bearing brick, its walls about 1.8 m thick at the base, stripped of ornament and curving out at the top like an Egyptian cornice. The Reliance Building (1890–95), completed by Charles Atwood, is almost all glass in a thin steel frame clad in white terracotta: a curtain wall avant la lettre. Holabird & Roche’s buildings standardised the wide tripartite “Chicago window”: a fixed central pane between two narrow opening sashes.
Louis Sullivan, in partnership with the engineer Dankmar Adler, gave the new type its theory and its most eloquent form. In the Wainwright Building in St Louis (1890–91) and the Guaranty Building in Buffalo (1894–96) he divided the façade into a base of shops, a shaft of continuous piers and a crowning attic, and covered the terracotta with ornament of intricate, plant-like geometry. His essay of 1896 gave the world “form follows function”.
The World’s Columbian Exposition of 1893, laid out by Daniel Burnham in white Beaux-Arts classicism, turned American taste back toward historical styles, and Sullivan’s career declined. But his pupil Frank Lloyd Wright carried his ideas forward, and when the European modernists discovered the Chicago frame in the 1920s, they recognised it as the ancestor of their own architecture.