Aluminum is such a ubiquitous material in 20th-century architecture that it is hard to appreciate how relatively late it came on to the scene. Aluminum had considerable advantages, including its light weight, its malleability, its corrosion resistance, and its alloyability for special properties. For the first third of the 20th century, however, it had to compete with similarly reliable materials, especially steel. Nevertheless, aluminum was seen as a thoroughly modern material without historical associations, making it indispensable to the Modern movement. This did not preclude some designers from using the material for historicist styles, but its functional role in architecture kept pace with architectural design and building technology. The particular strengths of aluminum were proven during World War II in a wide range of applications. However, after the war, the primary producers put aluminum into large-scale market development to advocate for its use in all sectors, architecture ...