The Chicago School developed during the late nineteenth century. The key event was the Chicago fire in 1871, which was caused by wood buildings and high population density. It finally became clear that new larger cities had to builded on reinforced concrete and steel, and had to grow vertically. The first modern skyscrapers were born.
After the fire, they began to build buildings with steel frame (more resistant to fire). The first skyscraper ever was built by William Le Baron Jenney in 1885 and took the name of Home Insurance Building; was ten floors high and had a steel frame even if not visible because inserted in the masonry. The building was demolished in 1931.
The architecture of the school is rational and functional (as it uses the ground); functional so as not to require any stylistic device and the function of the buildings can also understand from the outside; it is still the first architecture released by the European tradition.
The buildings are characterized by steel structures with masonry coating, leaving a large surface area and limiting the amount of external decoration. Sometimes in the skyscrapers of the Chicago school they were inserted elements of Neoclassical architecture.
Icons of the CHICAGO SCHOOL
Leaders of the movement were: Daniel Burnham (1846-1912) working with John Root (1850-1891), William Holabird (1854-1923), Martin Roche (1855-1927) and Louis Sullivan (1856-1924 ), which is associated with Dankmar Adler (1844-1900).
Monadnock Building built between 1889 and 1891 by architects Burnham and Root. The initial idea was an ideogram of the Egyptian papyrus column, but then the historical details were eliminated to leave a brick space with outward curvature and a frame at the top.
Info and image sources: http://www.greatbuildings.com/buildings/Monadnock_Building.html
Another symbol of the Chicago school is the Auditorium Building, designed by architect Louis Sullivan between 1889 and 1909. The building consists of two floors; the floor is of ashlar limestone and the outside is constituted by a smooth limestone.