Chicago School is the historical name of an architectural style that developed in the city of Chicago at the end of the century and beginning of the century, pioneering the introduction of new materials and techniques for the construction of large commercial buildings and the first skyscrapers.

It emerged in the United States, where historical references (historicist architecture) have less weight and importance than in Europe. The socioeconomic context is that of a very prosperous city with considerable population growth. The Great Fire of Chicago (1871) left most of the city destroyed, which meant having to rebuild it and gave urban planning maximum relevance. The need to create such a considerable number of new buildings gave rise to the emergence of the school, providing a demand for projects that no other place could match.[2]​.

There was great speculation about the land, which stimulated architectural solutions that involved vertical construction: many elevated floors on a reduced floor. The number of floors of the first school buildings (between 10 and 16) is quite modest by later standards, but for their time they were quite an achievement. At the same time, the first electric elevators appeared. The different architects and architectural workshops of the Chicago school proposed similar solutions among themselves, which determined the definition of a true common architectural style: concrete pillars as support or foundation (which solve the difficulty of building on a sandy and muddy soil), metal structures (already experienced in the iron architecture of the century) covered according to the function of the building, continuous windows that occupied most of the facades (what would later be called "curtain wall") and the elimination, in many In some cases, load-bearing walls. Buildings with very thick stone walls were no longer created, in favor of attractive masonry facades that suppressed decorative elements (common in eclectic architecture at the end of the century).

The models created in Chicago soon began to be emulated in other cities in the United States, and are at the origin of the architectural renewal of the first third of the century (architectural functionalism, Bauhaus, Modern Movement).

The architectural verticality and the abandonment of the load-bearing wall (almost unnecessary) is accentuated and modulated by the rhythm of the carpentry, the straight lines and the balanced and constant dialogue between the solid and the translucent, the latter being the most predominant and enriching of both the exterior language and the interior spaces, generating more than enough lighting.